The Influence of English as Medium of Instruction (EMI) on the First and Second Language Acquisition of Bilingual School Students: A Case Study

: English as a Medium of Instruction (EMI) is a term used for learning activities where English is used as the main language. This approach is widely adopted by bilingual schools as it allows learners to learn both their first and second language at the same time. While EMI has many advantages, the impact of this method on children's first and second language acquisition remains largely unknown. Therefore, through a case study, this research aims to examine the effect of EMI on children's first and second language acquisition in bilingual schools. This research will be conducted in a school that applies EMI in the Purwokerto area, namely Tiga Bahasa Putera Harapan School, with a sample of grade 3 students and teachers as respondents. This sample is randomly selected using a convenience sampling technique. Data for this study will be obtained through observations, speaking tests in Indonesian and English, and interviews. The results of this study show that there is no significant difference between the average English score (85.47) and Indonesian score (84.76) of students taught using EMI. Despite its status as an international standard school, national values and love for the country are still instilled through various curricular and co-curricular activities. This shows that with proper management, EMI does not affect the first and second language acquisition of children attending bilingual schools. To improve children's English proficiency, English needs to be introduced early through environmental conditioning that supports the use of English in daily life.


INTRODUCTION
English as a Medium of Instruction (EMI) can be defined as the use of English as the main medium of instruction in learning, including English and non-English language learning (Ernawati et al., 2021;Paris et al., 2022;Qomariah et al., 2022).The use of English as the language of instruction in bilingual schools has increased in the last two decades because the use of English offers the benefits of learning two languages at once, a first language and a second language (Ernawati et al., 2021;Escobar-Alméciga, 2022;Qomariah et al., 2022;Toth, 2018).
First language acquisition refers to the process by which children learn their native language.This process is called language development or language learning and involves both conscious and unconscious processes (N.C. Ellis, 2006).The acquisition of a second language is the process by which a person learns a foreign language.This process is usually more difficult than the first language acquisition process because we are required to learn to understand and use a different set of rules and structures than the first language (Freeman & Long, 2014;Ortega, 2013;Tomlin, 1990;VanPatten & Williams, 2015).
Many studies have proven that EMI has positive impacts on students' language mastery.Some of these positive impacts include making it possible to study learning material content in two languages at once, this can increase student engagement and performance in learning academically and non-academically (Ernawati et al., 2021;Lei & Hu, 2014;Qomariah et al., 2022).Moreover, EMI implementation can improve learners' English language skills (Paris et al., 2022).In line with this, Nur (Nur et al., 2023) stated that teachers support the implementation of EMI in schools because they also believe that the implementation of EMI brings many benefits to students, one of which is the improvement of English language skills.
On the other hand, several studies also state that EMI can have negative impacts on students.First, it may reduce students' motivation to study due to the use of English itself.Second, EMI can also reduce students' language skills because the learning load is too high (Barnard, 2014;Simasiku et al., 2015).Third, many students feel a lack of confidence since they cannot speak English well.This makes the interaction in the classroom passive (Nur et al., 2023;Ryhan, 2014).Fourth, from the institutional side, the lack of institutional readiness in preparing policies and curricula that accommodate national and international standards, the absence of standardized tests for bilingual schools, and the absence of a model that can serve as a reference for the implementation of EMI (Barnard, 2014;Ryhan, 2014).
Although many studies have examined the effectiveness of EMI in learning, most of them are at the tertiary level.It is still rare to find research that examines the effect of EMI on children's language acquisition, especially in bilingual primary schools that have long implemented EMI.Therefore, research on evaluating the implementation of EMI in bilingual schools is needed.Bilingual schools are educational institutions that use more than one language of instruction, usually a first language and a second/foreign language (Jayanti & Sujarwo, 2019).In Indonesia, the existence of bilingual schools has become more widespread since 2005 with the launch of a learning program called Pilot International Standard Schools (RSBI) through Law No. 20 of 2003 (Ernawati et al., 2021).This program aims to improve academic abilities while honing students' language skills (Ernawati et al., 2021;Qomariah et al., 2022).However, the implementation of EMI does not run smoothly.Many challenges must be faced, such as uneven levels of English language skills, teachers' lack of ability to provide instruction using foreign languages, and lack of student interaction due to limited language skills.This makes learning ineffective (Ernawati et al., 2021;Qomariah et al., 2022).
Regardless of the advantages and disadvantages of bilingual schools in supporting international language acquisition, agreement regarding when children should start learning a foreign language is still a matter of debate.Most language experts believe that the earlier the better (Team, 2022).This is because during childhood the child's brain is like a sponge and can absorb anything easily.Apart from that, language experts say that children can learn more than one language at once, just like learning their mother tongue (Kurnia, 2017;Rintaningrum, 2015).
On the other hand, there is concern that the process of acquiring these languages can influence each other, confusing children which will result in errors in understanding the two languages (Fadillah, 2009).This sparked concern from the Minister of Education so that English was removed from the elementary school curriculum through Minister of Education and Culture Regulation No. 67 of 2013 (Law Number 67 of 2013 concerning the Basic Framework and Curriculum Structure of Primary Schools/Madrasah Ibtidaiyah, 2013).This is intended so that students can focus on maturing their mastery of the National Language, namely Indonesian.
The existence of pros and cons related to learning English for children shows the need for a study that examines problems related to learning English for children which include: (1) How is English mastered by children who have learned English from an early age, (2) ) How is the mastery of Indonesian by children who study at school using English, (3) What is the impact of the introduction of English at an early age on the mastery of the National Language and the spirit of nationalism of children.Therefore, this research aims to determine the effect of implementing EMI in dual language schools on students' first and second language acquisition.

METHOD
This research aimed to find out the effect of English as a Medium of Instruction (EMI) on students' first and second language acquisition in bilingual schools.Qualitative method was the best method for this research because this method is the best method for understanding social phenomena and human problems (John W, C., & Creswell, 2018).In other words, this research examines a problem from the perspective of humans as research subjects.The problem studied in this research is the use of English in bilingual schools in Indonesia.The stages of this research included preparation and coordination, observation, interviews, data analysis, and conclusion.
This research was applied to 3rd-grade students of Tiga Bahasa Putera Harapan Elementary School.This school is one of the private schools in Purwokerto that applies EMI in learning.Grade 3 students were chosen because they belong to the category of young learners, which are school children aged 3-12 years old (Bakhsh, 2016).This research focused on young learners because they are still in the process of acquiring their mother tongue and meanwhile, at the same time, at school, they are exposed to a foreign language, namely English.It was assumed that the understanding of the first language and the process of acquiring the second language will influence each other to form a separate language called learner language (R. Ellis, 1997;Ortega, 2013).
The sample of this research was 3 rd year students as many as 36 students.An English teacher and a science teacher were chosen as the respondents.The sample and the respondents were chosen by using a convenience sampling technique.This technique is the simplest and easiest sampling technique to get respondents based on proximity to the researcher to obtain maximum data (Etikan et al., 2016).The inclusion criteria in this study are those who use Indonesian as their first language/daily language and those who have experience using EMI in learning.
The required data is obtained through observation, documents of students' Indonesian and English scores, and interviews with all respondents.In order to obtain a picture of how EMI is being implemented both inside and outside of the classroom, observations were made.These included asking whether teachers and students use English exclusively in the classroom or if they code-switch, using English with Indonesian inserted to communicate at school.At least two classes were observed: one that was taught in English and the other that wasn't.Using a semistructured model, the researcher prepared a list of fundamental questions to ask before the interview, but as the interview progressed, the questions became more open-ended as a result of the researcher's ability to go deeper into the respondents' responses (Alshenqeeti, 2014).In order to allow respondents to answer to the researcher's questions more freely, this interview was conducted in Bahasa Indonesia.The interview's goal was to learn what the teachers and students thought of EMI and how it affected their language learning.The instrument used in this research was the interview guideline.As the interview was semistructured, the instrument required was a list of questions with general points or guidelines.The interview will develop flexibly depending on the respondents' answers.Data from observations and interviews were grouped into the same categories.All interview results were written down and analyzed using thematic analysis, namely an analysis technique that emphasizes reading and coding data (Braun, V., & Clarke, 2006).The final stage was concluding the findings obtained.

RESULT AND DISCUSSION
This section describes the findings obtained from the observation, Indonesian and Englishspeaking test, and interview.These findings were analyzed and discussed to find out the impact of EMI implementation on the first and second language acquisition of bilingual school students.

Observation Result
Puhua School, well known as Putera Harapan Trilingual School, is the only international school in Purwokerto.After a long history, Puhua School was re-established on April 30 th , 2006 at S. Parman Street, Area of Mini Stadium, South Purwokerto, Banyumas, Central Java.As an international school, Puhua School implements three curricula, Indonesian National Curriculum, Chinese Curriculum adopted from Hebei University China, and Pearson Edexcel Curriculum UK.The teaching and learning process in Puhua School uses the students-centered approach in which the students are stimulated to be active.Moreover, it emphasizes noble values and character building.
The learning process is delivered in three languages, English for English, Computing, Math, Science, and Global Citizenship Subjects, Chinese for Chinese and Di Zi Gui Subjects, and Indonesian for General Basic Subjects.The students use these three languages in communicating with their friends and their teachers inside and outside the class.They have to speak in Chinese when they talk to Chinese teachers, they have to speak in English when they meet English teachers, and they use English and Indonesian in interacting with their friends and school staff.In Puhua Primary School, these languages are introduced in the first year.As a result, in the sixth year, they have been able to communicate fluently by using these languages.
Although in general students can adapt well to the use of these three languages at school, the process of forming this habit is not easy.Especially in English usage, some students keep using Indonesian when they communicate with their friends or ask a question to the teacher.But here, the teacher keeps responding in English so the students are immediately aware of their mistakes and switch their language.Moreover, their language proficiency is varied.Some students are very fluent in English and some others need to be guided in expressing their ideas.This condition requires the teacher to have good teaching skills so that all students are facilitated to learn and can be active during the learning process.
The other problem is about code-switching.Code-switching is the act of using multiple languages together.Code-switching can happen in the context of speaking a different language or switching the verbiage to match that of the audience.Proper code-switching requires maturity in acquiring the language.Students sometimes mix the language whether in the use of words, phrases, and sentences.However, it is viewed as the process of learning.With the commitment of all the parties involved at school, these mistakes will gradually disappear and turn into new language acquisition.

Students' English Proficiency
Figure 3 overviews the distribution of students' English Course scores.The scores range from 71,75 to 96,94 with the average score being 85,47.These scores are a little bit higher than the Indonesian scores but it is not significant since the range is wider.The mode is 88,94 and the median is 88,79.It shows that the students with above-average scores are more than those with under-average scores.However, it is considered very good since 100% of the students pass the minimum score.

Indonesian vs English Scores
Figure 4 describes the comparison between students' English scores and Indonesian scores.The blue line is the English scores and the red line is the Indonesian scores.Overall, it can be seen from the figure that the students' Indonesian scores and English scores are in balance.Their averages are quite the same namely 84,76 for the Indonesian score and 85,47 for the English score.Most students having high English scores have high Indonesian scores as well and vice versa.Only a few students show different patterns.Some students have high Indonesian scores but low English scores are student numbers 2, 12, and 20.On the other side, some students have high English scores but low Indonesian scores are student numbers 10, 15, 24, 28, 30, 33, and 36.Based on these scores, it can be inferred that the student's language proficiency applies to all languages.Those having good proficiency in one language tend to have good skills in the other language as well.So, the languages learned at the same time do not have negative effects on each other.There are five general factors contributing to individual differences in learning a language.They are age, aptitude, cognitive style, motivation, and personality.The age, adults learn a language through formal instruction and they have greater memory and the ability to stay focused and understand the formal features of a language.On the other side, children learn a language naturally like their mother tongue.Thus, children's language tends to be more natural and nativelike but less accurate.Second, aptitude refers to the special ability involved in language learning.It is one of the strongest predictors of success in language learning.Third, learners having high motivation and needs in learning the target language will be more successful than learners who have low motivation and needs.Last but not least, personality factors like confidence and anxiety as well as the cognitive level are the other factors determining the success of language learning (Fadillah, 2009).

Interview Result
Based on the result of the interview, it was found several points namely the policy of the usage of three languages at school, the teachers' and staff's proficiency requirement for those languages, the obstacles related to language use at school faced by the teachers and students, and the teacher's opinion on the use of EMI.These results were filtered, classified, interpreted, and validated by confirming the results to the respondents.The results of the interview were summarized as follows.
Sekolah Tiga Bahasa Putera Harapan, well known as Pu Hua School, applies three curricula namely the Indonesian National Curriculum, Pearson Edexcel Curriculum, and Hebei University Curriculum.Regarding this policy, this school emphasizes the use of three languages during the process of teaching and learning: Indonesian, English, and Chinese.The students have to use the appropriate language when they meet their teachers inside and outside the class.For example, when they meet English teachers, they have to speak in English and when they meet Chinese teachers, they have to speak in Chinese.Of course, to habituate this policy is not easy.There are many obstacles faced by the teachers and also the students.
From the teachers' point of view, most of them experience problems in mastering these languages.English teachers cannot speak Chinese fluently, and vice versa.However, to be a teacher in this school, there is a requirement to master English or Chinese proven by a language certificate and recruitment test.To overcome this problem, the school facilitated the teachers with English and Chinese language training and collaborated with a language development center.The other problem is about the international curricula applied.The teachers need much effort to adapt and learn the curricula, and the international standardized output also gives more challenges to the teachers.
From the students' perspective, the student's biggest problem is familiarizing them with these three languages, making them accustomed to using the right language based on the addressee and switching it when they speak to the other.Many students keep speaking in Indonesian although the teachers give responses in English or Chinese.The other problem is the students' varied language proficiency.Some students can use the language fluently and participate actively during the learning process, and some others are still struggling to convey their ideas in the correct language.As a result, there is a gap between the active students and the low students.Not a few students like to mix languages or use certain language rules for other languages.
In linguistics, this phenomenon in which the first language interferes with the second language is called first-language interference.This process includes transferring the linguistics habit of the first language, and the mistakes learners make in SLA.The two parts have a strong connection with each other.However, in some cases, the transfer between first and second languages contributes a negative effect on SLA, which is called the first language negative transfer, because it is less possible that the first language and second language have a very similar linguistic system.There can be many different conditions in SLA, for example, the first language and second language may be similar in structure which means that some particular structures in the first language can be found in the second language, or some structures in the first language are not valid in the second language or compared with the first language, the second language may have a distinctly different syntactical structure order (Ren, 2023).Nevertheless, it becomes a challenge for the teachers to help the learners acquire the second language through their first language acquisition and avoid errors in language acquisition in the future.
Regarding that children are still in the process of acquiring their first language, most of the teachers agree that international language or second language must be introduced as early as possible.The earlier children learn the language, the better results that they can obtain.Additionally, the children's environment also plays an important role in the process of mastering the language.The children whose parents can help them to learn the language at home, whether they know the language or they facilitate the children with additional language courses, tend to master the language better than those who learn the language at school only.However, it is undeniable that maturity in mastering the first language affects the mastery of the second language in return.But, by the time of learning and the process of building habits, this error will turn to new language acquisition.

The Impact of English as a Medium of Instruction on the First and Second Language Acquisition
In 2013, through Minister of Education and Culture Regulation No. 67 of 2013, the Government removed English Language Subjects from the Elementary School (SD) curriculum (Kemdikbud, 2013).The aim is for elementary school students to improve their mastery of Indonesian first before studying a foreign language.Based on the 2013 Curriculum (K13), English is not required to be taught in elementary schools.However, some schools still teach English as local content.Fortunately, the 2013 curriculum policy has been evaluated.In the independent curriculum initiated by the minister of education and culture, Nadiem Makarim, English has become one of the main subjects in primary school again.
Indeed, the mastery of the first language, somehow, affects the process of mastering the second language.The process of transferring the language involves what is called positive transfer and negative transfer.Positive transfer is when the first language and the second language are structurally the same so that the mastery of the first language aids the second language learning.Meanwhile, the negative transfer is when the rules of the first language are different from the rules of the second language.Negative transfer creates areas of difficulty, for example, most English language learners tend to learn content words first rather than function words (Fadillah, 2009).
Considering this issue, teachers in Pu Hua School disagree that introducing English at an early age will diminish the mastery of the National Language, Indonesian.The students' scores mentioned above proved that although English is used as a Medium of Instruction for several subjects, it does not affect the students' Indonesian language proficiency since the average scores in both subjects are considered good, namely 84,76 for Indonesian subjects and 85, 47 for English subjects.The use of English in this school does not exclude learning Indonesian, both are taught in the same position, namely as the language of instruction.Moreover, students not only learn English and Indonesian at the same time, they also learn Chinese.However, with the discipline in establishing the rules, the students are trained to manage themselves, when to use English, when to use Indonesian, and when to use Chinese.Of course, this cannot be separated from the role of teachers and all staff who are committed to creating a conducive atmosphere that supports the use of these languages at school.Apart from that, it is supported by an international curriculum which allows students to have international standard skills.
According to Yen, et al., there are some factors influencing the process of language learning, they are internal factors and external factors.Internal factors include learners' autonomy, motivation, and attitude towards language learning.External factors include the teachers' pedagogic skills, teachers' language competence, teaching approaches, assessment methods, socioeconomic backgrounds, and learning environment (P.H. et al., 2019).When these factors work well, better language acquisition is possible to achieve.

The Impact of Introducing English at an Early Age on the Mastery of the National Language and the Nationalism Spirit of Children
In this era of globalization, English is no longer a foreign language to our society.English is commonly found around us such as on gadgets, electronic devices, on the packaging of dairy products, and also in public places.Mastery of English which is recognized as a lingua franca is very important to survive in the international world.Currently, English is also used as a requirement in various fields such as student graduation, educational scholarships, job applications, and others.This makes the community's need for mastery of English is increasing and becomes an added value for individuals.Therefore, many parents want their children to master English as early as and send them to international schools.
This phenomenon has negative effects on our national language, Indonesian.Many parents are prouder of their children being able to speak English than when they can speak Indonesian properly.Many people also use English to emphasize themselves to look cool (Apriana, 2019).Nowadays there is also the term "Jaksel" language, which is Indonesian mixed with English to make it look cool and is commonly used by young people in the South Jakarta area.This shows a waning sense of love and pride in the national language.
However, although Pu Hua School is an international school, it is committed to building nationality and introducing the diversity of Indonesian culture through curricular and cocurricular activities.Some of the school cultures showing nationality are the flag-raising ceremony every Monday, National Day Commemoration, and cultural events like art Indonesian traditional art performances.These events are regularly conducted to instill the value of nationality and love for the homeland.Although the students learn by using the international curriculum, they are educated not to forget the local wisdom as the national identity.Indeed, this school emphasizes on not only the academic skills but also the soft skills and the noble values of the students as a provision to become a useful human being for the nation and state.

CONCLUSION AND SUGGESTIONS
In conclusion, mastering English as an international language gives many advantages for individuals.Language acquisition is best occurring at an early age when children are in their critical period.To get a better mastery of English, it needs to be learned as early as possible.Besides, a supportive environment also plays an important role in the process of language learning.Considering the issue that introducing English at an early age may diminish the existence of Indonesian as the national language, this study revealed that the use of EMI in primary bilingual schools does not have a significant impact on the student's first language acquisition.With good curriculum management and a commitment to creating a learning environment that supports the love of the country and local wisdom, the use of English in learning does not affect students' sense of nationalism.
This study limits the research focus to the use of EMI in elementary bilingual schools to determine its effect on children's national language acquisition.However, a study on international school applying full English is still needed to get more comprehensive data on the process of children's language acquisition.For future research, it is recommended to dig deeper into this phenomenon so that its impact does not damage our national language, Indonesian.

Figure
Figure 1.Class Observations

Figure
Figure 4. Indonesian Vs.English Score

Figure 5 .
Figure 5. Flag Ceremony and Boy Scout: Regular Activities to Build Nationalism and Character