Using Instagram for Teaching Idioms to Iranian Upper-intermediate EFL Learners

In this study, the efficacy of using Instagram as a smartphone assisting tool on teaching idioms to Iranian upper-intermediate EFL learners was examined. Oxford Placement Test (OPT) was utilized to determine the level of the learner's proficiency. Then, 60 selected participants were divided into two groups namely experimental and control groups. The learners in the experimental group learned idioms through Instagram (pictures, examples, and texts) and the learners in the control group learned them through the traditional method (texts, meaning, and examples). T-test was used to determine the significance of the experimental group improvement in learning idioms compared with the control group. The findings showed that the experimental group learners outperformed the control group learners and the increase in their scores was significant showing that Instagram is a good application for learning idioms. The results of this study might be useful for both EFL students and professors to learn and teach better.


Introduction
Recently, mobile-assisted language learning (MALL) has received considerable attention from a variety of researchers. Some of them are concerning with the possibilities and obstacles, some with the impact of mobile learning on education, some with the technologies, and some with the educational environments. It has been proved that the smartphone can be used for learning English due to the availability of lots of applications like WhatsApp, Viber, Line, and Instagram that could be used in this area (Cakmak, 2019;Rajendran & Yunus, 2021). Instagram can be in the service of learning language, especially in some important aspects such as learning idioms. This application benefits from an interactive environment and enables a learner to look at a photo and then leaves a suitable feedback. With this, the learners are capable of seeing a photo and making an opinion without having it in a context. Idiomatic terms are employed in all practices of speech: in conversations, lectures, movies, radio broadcasts, television programs, and so on. Moreover, their employment is so public in English that it appears very problematic and sometimes unusual for L2 learners to act well in an L2 communication context with lacking the understanding of idioms (Fotovatnia & Khaki, 2012). Hence, learning English idioms is important; each L2 learner must be prepared to deal with these contests (Al-Khawaldeh et al., 2016). In fact, the L2 learners must not only cope with the grammatical structures and vocabulary of the target language, but also engage in the beliefs of L2. As a form of metaphorical language, idioms are used inescapably in both spoken and written speech; however, mostly because of their metaphorical nature, they are often reflected challenging to acquire (Miller, 2020).
Recent studies have proved some positive aspects of Instagram and mobile assisted language learning for students in different countries (Gonulal, 2019;Rajendran & Yunus, 2021). However, it is necessary to elucidate the impact of Instagram as mobile assisting tool on teaching and learning Idioms. Hence, the main goal of this study is to investigate the effects of using Instagram (text and picture) on English idiom learning in Iran. In vocabulary acquisition, one of the most important issues is the ability of L2 learners to remember words for a long time. Some evidence recommends that when primary learning takes place under more difficult conditions, preservation might be enhanced at the end (Steinel et al., 2007). In order to fulfill the purpose of this study, the following research questions have been raised. Research Questions: RQ 1: Does using Instagram have any significant effect on learning idioms among Iranian upper-intermediate EFL learners? RQ 2: Are students who use Instagram more successful than those who use traditional method for learning idioms? RQ 3: What are the Iranian upper-intermediate EFL learners' attitudes toward learning idioms through Instagram? Research Hypothese: The following null hypotheses were made based on the research questions: H0 1. Using Instagram has no significant effect on learning idioms among Iranian upper-intermediate EFL learners. H0 2. The students who use Instagram are more successful than those who use traditional method for learning idioms.

Literature Review
From the 1970's, there was an interest toward employing communication skills rather than intellectual ones for second language teaching. Nowadays, communication is considered as the central motive for learning a language and for many young EFL teachers, the only teaching method that they have preferred is communicative teaching. However, the Communicative Language Teaching (CLT) has different meanings among the teachers. To some of them, it merely means a more importance on the usage of the target language in the classroom, with a greater emphasis on orality. For others, communication brings about the exchange of unfamiliar information between speakers. Lastly, some teachers realize communication as a cultural-bond system for building meaning. Despite the different descriptions of CLT, all the teachers seem to agree with the communicative method (Alamri, 2018;Wei et al., 2018). On the other hand, the history of technology assisted learning goes back to early sixties, which novel technological advances have stimulated and supported innovative state-of-the-art learning scenarios (Sandberg et al., 2011).
ICT is often denoted as a generic term for the Information Technology (IT); nonetheless, it is a more detailed term with wider applications that highlights the part of unified communications and integration, telecommunications, audio-visual systems that allow operators to collect, transmit and access to computer data and necessary business software, middleware, and storage (Ghasemi & Hashemi, 2011). The practice of ICT in education leads to more student-centered learning situations. Specifically, the character of ICT in education is fetching more and more significant by the current fast moving towards digital media and information. According to Anderson et al. (2002), in a short time, ICTs have turned out to be one of the elementary component of modern society. Meanwhile, many countries now regard understanding and utilization of basic skills of ICT as a part of their education. A great deal of studies have confirmed the values of ICT in education (Al-Ansari, 2006). In line with technological advances, particularly in smartphones, a plethora of beneficial applications are now available to aid people in numerous everyday jobs. Among them are mobile applications for learning new languages like English. The field of education has also been affected by ICTs, which have undeniably affected on teaching, learning, and research (Yusuf, 2005). ICTs are likely to hasten, augment, and extend skills, to inspire and engross students, as well as strengthening teaching (Lemke & Coughlin, 1998). However, the advance of ICTs such as internet, multimedia, electronic mail, collaborative platforms, and Apps, certainly impacts on the process in which they use in every day classroom teaching and learning.
In utilizing ICT, students try individualistically with technologies to arrive at a definite level of mastery in learning. Meanwhile, it offers flexibility to learners, which are required for the quality of learning. The usage of ICT in language learning not only includes educational variations for teachers but also encompasses environmental changes for learners who are conventionally accustomed to face-to-face actions in classrooms environment. While a growing number of learners have access to online technologies of ICT, they find it a bit challenging to use it in an educational setting. Consequently, ELT teachers are adapted to frequent subject innovations, but not inevitably more inventive or open to novel concepts. There was sign of many problems in attaining technical skills in the start, and it took about a generation to be resolved. By helping the students to find value in learning through the employment of various smartphone apps, while maintaining high standards of student performance, will encourage the motivational levels of all of them. Particularly, transportable gadgets such as smartphones coupled with smart teaching apps allow learners to learn any lesson in any place and in every time. Although the mobile phones, at first generations, had not much functionality than just simple phoning and texting, the latest generation of them provide far greater capabilities of multimedia, location-based learning, and fascinating games to boost the learners' pleasure and enthusiasm (Caudill, 2007). In addition, Internet accessibility lets immediate communication with others, whereas GPS shows to the specific location of the learner to access content that is relevant to a learner place. What is more, increasing bandwidth eases the combination of different media types for further boosting the learning process.
Mobile phones are an educational means with inordinate teaching potential because of their popularity among young adults and their economic capacity for one-to-many. Furthermore, the positive aspects seem to compensate their drawback of small screens. To maximize the benefits of smartphone-based learning, the software designer should be considered the needs of learners and learning styles of conventional paper-based platforms. To learners of the `m-generation' (Prensky, 2005), the delivered information via mobile phone is controllable while the one-shot massed paper material in a rather traditional manner fails to arouse their interest to study.
Most of previous studies expose the current movements of employing mobile devices to support language learning and demonstrates that MALL rises motivation of learners (Kim et al., 2013), and encourage collaboration and interaction (Goh et al., 2012). In this case, Thornton and Houser (2005) examined the use of mobile devices by Japanese university participants in a language learning context and the results proved the positive effect of mobile devices. Basoglu and Akdemir (2010) compared traditional flash cards on paper with digital flash cards and mobile phones. Their findings confirmed that the participants who had used the mobile application achieved better results. In another study by Solé et al. (2010), participants who reported working through mobile phones showed a better engagement in learning. Begum (2011) tried to investigate the possibility of using cell phone in the EFL classroom of Bangladesh as an instructional tool. After analyzing the data, it was showed that despite some challenges, cell phone has great potential as an instructional tool. Baleghizadeh and Oladrostam (2010) investigated the effect of MALL on grammatical accuracy of EFL participants. The results showed that the participants in the experimental group displayed better performance than the participants who were in the control group. Dashtestani (2013) investigated the attitudes of Iranian English as foreign language teacher toward the implementation of MALL. The result revealed that there were positive attitudes of the participants toward the use of mobile phones for language learning and teaching.
According to Chiu et al. (2015), the use of mobile device in language learning could improve students' language skills. It is because mobile devices provide some features and applications that support language learners to improve their language skills. Moreover, Krivoruchko et al. (2015) stated that through the implementation of MALL facilitates mobility to language learners and teachers. It means that language learners can learn their target language anywhere and anytime while, teachers can access teaching-learning material as well. In general, MALL has some benefits to teachers, students and learning process. Wagner et al. (2016) found that the respondents have positive perceptions in which they believed that MALL is good learning strategy to support their teaching learning process. As supported by Yudhiantara and Saehu (2017), they found that students' perception toward mobile phone to support classroom activities were positive. Classroom activities were supported by reading e-books that contained Phonology subject, playing audio and video file to get visualization of the Phonological concept, and operating offline dictionary. Oz (2015) stated that the successful integration of mobile technology in English learning does not depend on the technology itself, but it depends on some degree such as students' and teachers' awareness, and perception toward the technology in integrating to English learning. Therefore, it is important to know the users' perception toward technology in English learning in order to achieve successful implementation of technology in English learning (Shorfuzzaman & Alhussein, 2016). Grimshaw et al. (2017) reported that most language teachers were opened to engage their students in MALL, but they still worried with the limitation of MALL. In line with Azli et al. (2018), Mobile Assisted Language Learning as formal and informal learning can support traditional learning. It is said as formal and informal learning because it can be done both in the classroom and outside of the classroom. They found that the respondents had positive perception toward the use of MALL in classroom. They assumed that the use of MALL could enhance the teaching learning process. They also hoped that MALL can be used by educators to assist them in EFL teaching learning process become effectively. MALL researchers state that this ease of communication with teachers and peers is a major opportunity of the utilization of mobile phones for language learning (Dehkordi & Taki, 2018;Nah et al., 2008). Widiana et al. (2018) also found that tenth grade students had positive perception of MALL in learning English. Besides, students who had mobile technology tend to have more positive perception rather than students who had no mobile technology.
Alternatively, some MALL researchers believe that the use of mobile phones for language learning might facilitate the process of language learning while possible challenges can be accommodated or alleviated (Stockwell, 2010;Thornton & Houser, 2005). Despite general acceptance of the implementation of MALL in EFL contexts, several EFL experts have pointed out considerable challenges to the use of mobile phones for language learning and teaching. As Stockwell (2007) argued, one major obstacle to the use of mobile phones for language teaching is students' reluctance to use mobile phones for their educational and academic purposes. Thornton and Houser (2005) asserted that the small screen size of mobile phones would create another challenge to the implementation of MALL. High cost of the use of mobile phones for educational purposes might discourage students and teachers from implementing MALL in EFL courses accordingly (Stockwell, 2007). Similarly, limited presentation of graphics of mobile phones may act as another impeding factor (Albers & Kim, 2002). Therefore, it is expected that most limitations of mobile phones for language learning will disappear in the future. Dashtestani (2013) also asserted that there were some problems faced by Iranian English teachers in implementing MALL. The problems such as students may not use their mobile phones for academic purposes, small screen size and keyboard of mobile phones, low speed internet connection if there was no Wi-Fi or packet data.
An idiom is a common phrase or term that its meaning is different from literal and is not real, but it can be understood easily by their popular native users (Siyanova-Chanturia & Martinez, 2015). Since idioms mean something different from real mean, it is difficult for non-native speakers to use them correctly. For examples, the idiom "shape up" or "ship out" that means improve your behavior or leave out, might be said by an employer to an employee, but not to other people. To learn a language, a person needs not only to learn the words in that language, but also needs to learn idioms separately because they have different meanings. In some cases, to understand an idiom, it's necessary even to be acquainted with the culture where the idiom comes from (Wu, 2008).
About idioms teaching via ICI, one of the most important examples is mobile applications like Instagram. The use of Instagram as a didactic tool, combined with pictures, will help students to understand these idioms, which are the reflection of a culture. Thanks to development in technology, some educators have rapidly implemented the widespread wireless handheld devices to shape learning environments for students not only to extend their learning experience in outside of the classroom but also to provide students with scaffolds to enhance their learning and at the same time simplify peer collaboration and interaction with the instructor. The design of mobile and ubiquitous systems to support student learning has been emphasized by other researchers, in which, students' enthusiasm, interactivity, and learning efficiency were found to be positive. Besides simplifying individual learning from the cognitive standpoint, some researchers have focused their attention on nurturing joint environments for learning. So, it can be said that mobile devices in various educational fields require diverse instructional plans and the learning efficacy can cover an extensive range of cognitive and social interactions. Socializing on Instagram is mainly done through the like and comment functions.
More important motivation in using Instagram as a language learning tool, in this study, is that Instagram is a commonly used social media among young learners; so, including it in their learning process can be seen as a form of applying topics learned conventionally in class within their real life environment (Vie, 2008). Interestingly, the familiarity of young learners with Instagram can be seen as an advantage as it can lessen possible stress caused by integrating unfamiliar tools into learning activities (McBride, 2009). Lastly, ease of access to Instagram and availability in most handheld devices makes it more inviting to consider this platform for use in language teaching.
A plethora of studies have also been reported on the practice of various social media platforms like Facebook (Bowman & Akcaoglu, 2014;McCarthy, 2010) and Twitter (Krüger-Ross et al., 2012;Reed, 2013;Warren, 2012) in classrooms. Very few, however, describe the use of Instagram in language teaching. Bell (2013) stated the using of Instagram for college students' field trips in a library science course. Tekulve and Kelly (2013) and Salomon (2013) also conferred the positive experience of their institution's libraries in employing Instagram to reach their young audience in compared with other public media tools. More recently, a study showed that utilizing Instagram application had a positively significant effect on autonomous/dependent Iranian intermediate EFL learners' pictorial metaphors learning. Furthermore, both autonomous and dependent students had a positive attitude toward using Instagram application (Ahmadi 2021).
From the recent reported works, it can be resulted that via smartphone-based applications, specifically designed to aid people in learning new language, users can take full advantage of their usage of idioms and hence be easily familiarized with them in anywhere and anytime.

Research Design
There were two groups quasi experimental and control group, that they were all upper-intermediate. The pretest test was firstly taken by researcher and after treatment, the posttest was taken by changing the questions order. The number of correct responses for each participant were counted and data were analyzed by SPSS software. To answer the first research question of the study, t-test was used.

Participants
The participants were 60 upper-intermediate Iranian learners of English from Najafabad University, Isfahan, Iran. They were from 20 to 27 years old, Persian speakers learning English as L2. The volunteers were randomly separated into two groups: an experimental and a control. One of the two classes received idiom teaching through Instagram and for the other one traditional method was used. Both classes had one teacher to control the teaching variable.
The participants in the control and experimental groups received different treatments: Group 1, as a control group, gained idioms along with explanations, texts, meaning and example in the class. Group 2, as an experimental group, got idioms followed respective definitions, pictures, examples and texts in Instagram.

Instruments and Materials
The materials selected for this study were taken from textbooks that they study in their university. The materials are not normally topic oriented; however, the researcher chose some pictorial, colorful idioms and categorized them according to some topic, like animals, food, etc.
Oxford Placement Test (OPT) was used to determine the level of the learner's proficiency. It organizes learners in various levels according to language proficiency and their knowledge.
Pretest and posttest: There is a same taste for pretest and posttest. After treatment a questionnaire again use this test by changing the order of questions.
Questionnaire: Researcher made a questioner that was validated by giving to three experts and its reliability and validity were estimated. The questionnaire included 15 items that were five alternative questionnaires.
Validity of questionnaire: Validity means that content of data collection tools or the written questions evaluate exactly the studied issue.
Reliability of questionnaire: Reliability is one of the technical features of a measurement tool, which indicates to what extent the measurement tool will obtain the same results in the same condition. One of the methods for calculation of reliability is Cronbach alpha coefficient. For calculation of it, score variance of each question of the questionnaire and total variance of test must be calculated; then, Cronbach alpha formula must be used to calculate its value. According to variance of each question and variance of total test which was obtained, Cronbach alpha coefficient was calculated by SPSS software to be 0.951. Because the values more than %70 is desired in humanistic studies, so the reliability is valuated well and the obtained data of the research sample can be generalized by good probability to all people in the population.
Pretest -Prior to the lunching of the study, the researcher-designed pretest which was specifically designed to tap into the participants' Idioms competence in terms of comprehension of idioms language. This multiple-choice test contained 15 items. The examples of the pretest were derived from Instagram to test the required Idioms expression.
The tests required the participants to select the meaning of some Idioms statements from the given options. Because the aim of the present study was to check whether the participants learned the meaning of the idiomatic expressions or not, the multiplechoice items could be the best choice.
Posttest -The format of idioms and the content of posttest was the same as the pretest, and the number of the items of this test were the same as those of pretest but to remove test practice effect, the place of items and options was changed. It was used to measure the learning of idioms for test group.
Instagram application -To fulfill the study, Instagram application was utilized for both the students and teacher. In so doing, teacher as the researcher created a group including the experimental participants and sent them the pictorial idioms posts via the Instagram application.

Procedure
Prior to conducting the study, OPT test was taken by researcher who divided the participants into two groups: experimental and control group. Both were upper-intermediate. The control group learned idioms through traditional method as texts, meaning and example and the experimental group learned idioms through Instagram as pictures, examples and text.
At the end of the study, students were examined to see which group has learned the idioms better. A questionnaire was further used to show their attitude toward learning idioms through Instagram and traditional method.

Data Analysis and Results
Data analysis as a part of the scientific research process is one of the cornerstones of any study and research. Here, descriptive and inferential statistical methods are used in order to answer the designed questions and make decisions about approval or rejection of hypotheses.
At first, descriptive evaluation of variables such as test scores and surveys are investigated for two separated groups of traditional and Instagram teaching methods. Then one sample t-test and independent t-test were used for data analysis in order to test hypotheses and to generalize the results to the entire population. Then a researcher made attitude questionnaire to show the feelings of students about using Instagram as a virtual environment for learning idioms. Table 1 includes descriptive statistics such as mean and standard deviation of test scores, as well as minimum and maximum scores in two separated Instagram and traditional teaching methods. It is observed that the mean scores of subjects in Instagram method is 8.6 and in that of traditional method is 6.3. Frequency distribution of test scores for both groups is given in Table 2. At first, the test of level determination is performed and individual's level is determined. Then individuals with mean level and up have been identified. Table 3 shows the standard level determination based on scores obtained from the participants. Table 4 also includes descriptive statistics such as mean and standard deviation of individual's scores and minimum and maximum scores. As seen the mean score of individual's level determination is 43.25, which accounts for mean and up category. These 60 individuals were placed in two groups of traditional and Instagram groups for teaching and testing.

Normality Test of Variables
Kolmogorov-Smirnov (KS) test was used to investigate considered claim about data distribution of a quantity variable. In this test, the null hypothesis is the claim about the data distribution. In the current study, normality of data distribution is investigated by KS test. As indicated in Table 5, the results show that all factors in investigated sample follow normal distribution, because the level of significance is more than 5%. So, parametric statistic tests were used to test hypotheses.

Hypotheses Testing
First Hypothesis: Use of Instagram has not affected on learning idioms among English student with mean to high level. One sample t-test is used to investigate the first hypothesis. Since the scores of taken exam are in the range of 0 to 10, mean score variable is compared with numeral value of 5 in one-sample t-test. One-sample t-test results are provided in table 6. According to Table 6 and obtained level of significance, null hypothesis is rejected because the obtained level of significance of Instagram-based teaching method on test scores is 0.000 and it is less than 0.05. Therefore, mean of scores has significance difference compared with hypothetical mean of 5. According to the coded mean relating to the effect of histogram teaching method on the obtained scores, which was equal to 8.6, it was concluded that the effect of method on test scores is higher than mean. Therefore, use of Instagram was effective on learning idioms among Iranian upper-intermediate students with 60 participants and the first hypothesis was supported.
Second hypothesis: Students who learn idioms by Instagram are not successful than students who learn idioms by traditional methods. Independent t-test is used to investigate the second hypothesis. According to Table 7, results of Levene test is used for equality of variances of two populations. Because, level of significance is more than 0.05 for this test, so equality of variances is supported. Due to equality of variances, first table row is used to investigate difference of mean between the two teaching methods. Because the level of significance of mean test is equal to zero and is less than 0.05, it is concluded that mean of test scores has significant difference based on two teaching methods of Instagram and traditional. According to obtained mean for students' test scores in two separated method of teaching in descriptive statistic (Table 6) and because mean scores in Instagram teaching method group is equal to 8.6 and is more than mean scores in traditional teaching method group (6.3), it was concluded that students who use Instagram for learning idioms were more successful than students who used traditional methods for learning idioms. So, the second hypothesis is supported.
Regarding the 3 rd question of this research, "What is the attitude of students about learning idioms through Instagram?", one-sample t-test is used to investigate the third hypothesis. Since, the questions of the questionnaire which is teaching method is consisted of 5-point Likert, mean of related variable is compared with mean of questions that is numeral value of 3 in onesample t-test. Related test is as following. The results of one-sample t-test are offered in Table 8. According to Table 8 and obtained level of significance, because the level of significance for the effect of Instagram teaching method on feeling is obtained 0.000 and it is less than 0.05, null hypothesis is rejected. Therefore, the students' feeling to teaching method has significant difference with hypothetical mean of 3. According to obtained mean for the effect of Instagram teaching method on students' feeling to teaching method is equal to 3.97. Table 9 includes descriptive statistics such as mean and standard deviation of subjects' feeling about teaching methods as well as minimum and maximum scores in two separated Instagram and traditional teaching methods. It is also observed that the mean of subjects' feeling in Instagram method is 4.12 and it is high. It is also observed that the mean subjects' feelings in traditional method is 2.76, a mean value.

Discussion
According to the results of this study and respective statistical analysis, first hypothesis that is "the use of Instagram has effect on learning idioms among English learners with upper-intermediate level" is supported. Therefore, in line with the points proposed at the literature review section in chapter two, this study acknowledged the the advantageous role of MALL and justifies its extending use for language learning. Instagram with some general features like popularity, particularly among young adults, and its high potential for contextualized visual data, could be considered as a mobile language learning tool. Tarigan et al. (2021) presented the other way to use Instagram as an educational tool, which it was about digital storytelling that can be promoted when students contribute their own content to an authentic audience. Students can express their feelings as well. Thus, it can set up a positive learning atmosphere. Al-Ali (2014) mentioned that Instagram provided good opportunities to create more individualized learning experiences for language learner's prompts. Mansor and Rahim (2017) discovered that it is an efficient platform which it encourages students to interact with their other students. Furthermore, it seems Instagram Application could support autonomous learning as learners will consistently engage with a plethora of texts without the instruction or guidance of a teacher. Accordingly, Hafner et al. (2013) and Barton and Potts (2013) argued that Instagram can facilitate autonomous learning.
The second hypothesis, saying that "students who learn idioms by Instagram are more successful than those learned idioms by traditional methods", is supported by the results too. It may be because idiomatic terms are used in all forms of daily routines and speech and all of them are presented in Instagram in auditory and visually forms, in a similar way of routine speech. Hence, this opportunity helps the learners to become more successful in acquiring idioms. Since ICT provides an influential learning environment for students outside of the classroom and it is regarded as an active means for recommencing educational practice in any field, many countries make investments in ICT integration in education. As a main characters to employ ICT in educational contexts, teachers should be trained in how ICT can be integrated into the teaching process (Hismanoglu, 2012). This may be due to the ability of Instagram in effective teaching of idioms, which involves the ability to learn languages, have compassion to written and spoken language, and its ability to use a language to achieve a set of goals. This strategy is practical when a learner looks at a photo and then leaves an appropriate comment. With this, the learners can see a picture and make an opinion without being obstruct with text. Such a positive effect of Instagram has also been observed for learning Pictorial Metaphors by Iranian Intermediate Autonomous/Dependent EFL Learners (Ahmadi, 2021). Additionally, it has been reported that the ICT cannot itself obviate educational problems in the developing world. However, if used wisely, ICTs will facilitate developing countries to increase accessibility to and advance the excellence of education. Hence, the integration of ICT in education is imperative in nowadays' technologically competitive world. In case of its aptly adaptation, it will be a lifetime's learning process for the participants. In addition, the quality of learning with responsibility can be enhanced, which leads the learners to learn things more rapidly and effectively (Kirubahar et al., 2011).
The third question of study was that "What are the Iranian upper-intermediate EFL learners' attitudes toward learning idioms through Instagram?". In this context, the results showed that learners in the experimental group, which the participants had received instruction through Instagram, had a positive outlook toward utilizing Instagram Application. Also, to casting a look on the mean scores of both groups for posttests, possible reason for improvement could have lied in the fact that Instagram Application was motivating. Azli et al. (2018) argued that Mobile Assisted Language Learning can be done both in the classroom and outside of the classroom. They found that the respondents had positive perception toward the use of MALL in classroom. They assumed that the use of MALL could enhance the teaching learning process. Wagner et al. (2016) found that the respondents has positive perceptions in which they believed that MALL is good learning strategy to support their teaching learning process. As supported by Yudhiantara and Saehu (2017), they found that students' perception toward mobile phone to support classroom activities were positive.

Conclusion
In brief, it can be concluded that learning via a mobile phone and application is basically different from conventional classroom learning, in which it allows a learner to learn anywhere and anytime. Furthermore, Internet availability lets immediate communication with others.
On the other hand, since idiomatic terms are employed in areas of speaking and their practice is very public in English, it appears very difficult and occasionally unnatural for L2 learners to function effectively in an L2 communication context without familiarity with idioms. Hence, learning English idioms is an essential part of language learning step and each L2 learner must prepare to deal with it. In fact, the L2 learners must learn not only to cope with the grammatical structures and vocabulary of the target language but also, they should learn how to utilize idioms.
In this regard, Instagram can be used in learning idioms, which involves a learner looks at a photo and then leaves an appropriate comment. It may involve the audio, voice, music and some other feature, which puts the learner in a situation like normal life. With this, the learners can observe a picture and make an opinion without having idiom in the context.
The superior act of experimental group compared with control group might be related to the fact that they were provided with situations in which idioms were imagined by pictures, aiding them keep in mind idioms better (Zhang et al., 2011). The results also showed that using pictures could improve EFL learners' retention of idiomatic expressions to a significant extent because it could bring a great change in the experimental groups' retention and led them to go through significant comprehension. Thanks to the advantageous features of Instagram, it represented a positive attitude for learners.

Limitations
This study was not out of limitations. Firstly, this study did not have a large sample size. The participants of this study consisted of 60 upper-intermediate EFL students. Due to this fact, generalizing of the results should be done cautiously.
Secondly, it should be noted that this research has provided an overall picture of using Instagram on Iranian upperintermediate EFL students' and does not claim to provide a perfect picture of the upper-intermediate EFL students' positive improvement in all aspects of reading comprehension and it requires further research in this area.
The third limitation refers to participants' language proficiency. All the participants in this study were upper-intermediate EFL students. As such, the efficacy of Instagram on learning idioms cannot be generalized to the other levels.