Bilingual education

In bilingual education, students are taught in two (or more) languages. It is distinct from learning a second language as a subject because both languages are used for instruction in different content areas like math, science, and history. The time spent in each language depends on the model. For example, some models focus on providing education in both languages throughout a student's entire education while others gradually transition to education in only one language. The ultimate goal of bilingual education is fluency and literacy in both languages through a variety of strategies such as translanguaging and recasting.

Bilingual education program models
There are several different ways to categorize bilingual education models, one of the most common approaches being to separate programs by their end goal. This is the approach used below, though it is not the only possible approach. For a more comprehensive review of different approaches to bilingual education worldwide see bilingual education by country or region and intercultural bilingual education.

Maintenance bilingual education
In a maintenance bilingual education program, the goal is for students to continue to learn about and in both languages for the majority of their education. Students in a maintenance bilingual education program should graduate being able to have a discussion about any content area in either language. Two common forms of maintenance bilingual education are two-way/dual language immersion and developmental (late-exit) bilingual education. Both programs are considered language immersion programs.

Dual language programs
A program that utilizes two languages, known as a dual language program, typically places students in classrooms with a mixture of native speakers for each language. One popular approach to dual language programs is the 90/10 model, where in the early grades 90% of instruction is conducted in the student's native language and 10% is taught in their second language. As the student advances, this proportion changes until an equal amount of time is spent on both languages. Another model, the 50/50 model, starts with an even distribution of instruction time between the two languages right from the start of the student's education.

Late exit programs
In a late exit or developmental program, students all have the same native language. They tend to follow the 90/10 model described above and gradually transition from a majority of instruction in their home language to a more balanced split between languages as they progress through primary school.

Bimodal-bilingual programs
In a bimodal bilingual program, students are taught in two languages in two different modalities, typically a spoken/written language and a signed language. This type of program is common at schools serving deaf and hard of hearing students.

Transitional bilingual education
In transitional (early-exit) bilingual education programs, the goal is to provide education in a child's native language to ensure that students do not fall behind in content areas such as mathematics, science, and social studies while they are learning the new language. Unlike in maintenance bilingual education programs, when the child's second language proficiency is deemed satisfactory, they transition to using only that language. This approach is based on the common underlying proficiency model of bilingualism which posits that many of the skills learned in the native language can be transferred easily to the second language later. While the linguistic goal of such programs is to help students transition to mainstream, single language classrooms, the use of the student's primary language as a vehicle to develop literacy skills and acquire academic knowledge also prevents the degeneration of a child's native language.

English as a second language
English as a second language (ESL) programs are not considered bilingual education programs because they do not aim to have students become bi-literate in two (or more) languages. The goal of ESL programs is for English-language learners to learn English after having acquired one or more native languages. ESL is a supplementary, comprehensive English language learning program common in English-speaking countries and countries where English has an important role in communication as a result of colonialism or globalization. One common approach in ESL programs is sheltered English instruction (SEI).

Translanguaging
Translanguaging or language mixing is a strategy that emphasizes using all languages a student knows to support their learning. One example of this is allowing students to express themselves in either or both languages when discussing different academic content. Practicing translanguaging can help students more easily switch between languages.

Language separation
Language separation in a classroom refers to assigning a specific language for a particular time, content, or activity with the aim of helping students concentrate on developing their skills in that language. Bilingual programs often combine both language separation and translanguaging approaches to facilitate students in achieving bi-literacy.

Scaffolding
Instructional scaffolding can be used in all types of education, not only bilingual education. A teacher scaffolds instruction to provide the necessary support for students to learn the content. In a bilingual education classroom, this could look like pre-teaching content in the student's native language before teaching the same content in the second language.

Recasting
In bilingual education, teachers may use different techniques to correct students' language errors. One such technique is recasting, which involves repeating the student's statement with corrections for any grammatical or pronunciation mistakes, akin to how parents assist their children in learning their first language. Another technique is explicit correction, where the teacher directly points out the error in the student's statement.

Effects of bilingual education
This section focuses on the effects of bilingual education specifically, see Cognitive effects of bilingualism for information about the effects of bilingualism or multilingualism.

Benefits of bilingual education
The most obvious benefit of bilingual education is proficiency and literacy in two (or more languages). Fluency in multiple languages can lead to increased employment options as well as create more opportunities for intercultural communication.

Bilingual education can also support minority language speakers by communicating the value of their home or heritage language, resulting in increased self-esteem. Additionally, bilingual education models have been shown to improve student engagement and attendance as parent involvement in school activities.

Bilingual education supports students in becoming literate in both languages, which has been shown to increase reading scores for students in both languages. Researchers have proposed that this could be due to students in bilingual programs having an increased awareness of languages and their writing systems.

While there has been significant research on the "bilingual brain," research specifically on how bilingual education impacts brain structure and activation is fairly limited. Though much of the research on bilinguals shows that the benefits of bilingualism are maximized when children are exposed to multiple languages at an early age, as they are in many bilingual education programs. However, some initial research has shown preschool children in bilingual education programs have similar brain activation patterns in response to known and unknown languages as adults who have been learning a second language for several years.

Disadvantages of bilingual education
In many English-speaking countries, standardized tests are in English, so there is a push to maximize the time spent learning English. Proponents of this framing advocate for Structured English Immersion in which students spend the majority of their day learning about English and in English with scaffolded supports based on their current English knowledge.

Bilingual education requires teachers to be fluent and literate in both languages, as compared to English as a second language programs that only require teachers to have English fluency and literacy.

Bilingual programs for language revitalization
Bilingual education can also support language revitalization efforts in countries with endangered languages. These dormant languages are heavily intertwined with the culture, place and identity of the subsequent community, so the creation of bilingual programs to help re-awaken the endangered languages is extremely beneficial. Generally speaking, the official primary and secondary languages of a country are favored for bilingual programs, but there have been emerging bilingual programs to re-introduce an endangered language to a community. These education policies are fundamental to a communities' and next generation's identity development. An example that hindered this is that of the residential schools of Canada. Children were punished severely for speaking their mother-tongue, which has caused generational trauma among a plethora of Indigenous persons who attended these schools throughout the country. However, learning from events such as these, has helped spread awareness of language revitalization.

Bilingual programs for language revitalization are tricky; each language is different, and there is a lack of educational resources and training for teachers in that specific language. Furthermore, there is not enough research done on what the goal for bilingual programs is: is it cultural acknowledgment or bilingualism? Quite often there is a clash between the government educational policies and the actual implementation of said policies. That being said, there has been tremendous progress of working bilingual programs, one being in New Zealand. The Māori community in the Te Kōhanga Reo region created an early language childhood program that includes traditional customs of the culture. The program takes advantage of having native speakers while also recognizing that new and upcoming speakers can help the language adapt to more modern times.

Thanks to the emerging language revitalization programs, more communities can break free from an accommodation norm – feeling threatened to speak their native language due to political tensions, such as colonialism that still persists throughout most nations. The question of whose language and knowledge is more valuable should no longer linger with the help of these bilingual programs.