Immersion is a form of bilingual education used to describe programmes which serve language majority students and which use a second or foreign language to teach at least 50% of the curriculum during the elementary or secondary grades. Canada is the best and most known example: The federal government has been a strong supporter of establishing Canada as a bilingual country and has helped pioneer the French immersion programmes in the public education systems throughout Canada. In such programmes, English-speaking students, with no previous French language training, do all of their school work in French.
The term is also often used as a synonym of the 'direct method', a method of foreign or second language teaching which has the following features: (a) only the target language is used in class; (b) meanings are communicated 'directly' by associating speech forms with actions, objects, mime, gestures and situations; (c) reading and writing are taught only after speaking and (d) grammar is taught inductively, i.e. grammar rules are never taught to the learners.
French immersion education in Canada has been a success story. The majority of the research results have been positive, and each year, thousands of students across Canada graduate with excellent skills in both languages. The success is due to a number of factors: the excellence of the programme provided in the schools and the effectiveness of teacher training, and to a large extent the supportive attitude of parents and the broader society towards bilingualism.
With regards to foreign language teaching, 'immersion' methods have obviously very positive effects on spontaneous speech production and, in general, produce good results faster in terms of students' oral skills. However, evidence that such methods are more effective in improving students' general linguistic abilities, or that they produce any long-term gains for written and oral work, remains to be seen.
The claim that 'the best way to learn a language is through total immersion' is an overstatement. There is no credible evidence to support the claim that the more students are exposed to the target language, the more of that language they will learn. Research shows that what counts is not just the quantity, but the quality of exposure. Second-language input must be 'comprehensible' to promote second-language acquisition. If students are left to sink or swim in a classroom that uses a second language, with little or no help in understanding their lessons, they won't learn much of the second language. If native-language instruction is used to make lessons meaningful, they will learn more.
Case studies in England and the USA have indeed concluded that it is not the case that the more time students spend in a second language context, the quicker they learn the language. Several programmes have been developed on the model of French immersion, aiming at the acquisition of English by children of immigrant families. Over the length of the studies, children in bilingual classes, with exposure to their home language and to English, acquire English language skills equivalent to those acquired by children who have been in English-only programmes. This would not be expected if time on task were the most important factor in language learning.
Researchers also caution against withdrawing home language support too soon and suggest that although oral communication skills in a second language may be acquired within 2 or 3 years, it may take 4 to 6 years to acquire the level of proficiency needed for understanding the language in its academic uses.
In addition, the age of first immersion in a foreign language has an effect on ultimate attainment. Second-language learners immersed in the target language from an early age appear typically to attain native or close-to-native mental grammars. Those immersed in their teenage years or later appear typically to approximate less closely to the target language in their unconscious competence. Of course not all individual speakers conform to these patterns; i.e. some early starters may not be fully successful and some late starters may be very successful.
Research has also focused on EFL classes around the world. Most of such classes are typically taught by a non-native teacher of English and consist in most cases of learners from a single linguistic background and culture. Many teachers in this situation will endeavour to use English as much as possible in the classroom, giving instructions in English, teaching basic English classroom metalanguage, requiring learners to use English when asking questions, insisting that they use English in group and pair work and so on. This is all extremely positive and probably produces good results.
However, where the non-native teacher of English enjoys a particular advantage over his or her native-speaker colleague who is ignorant of the mother tongue of the learners is in the ability to use the mother tongue as and when it is required. The mother tongue can be used to provide a quick and accurate translation of an English word that might take several minutes for the teacher to explain and even then there would be no guarantee that the explanation had been understood correctly. (To avoid over-dependence on translation, some teachers have a policy of not giving a verbal translation of a particular word when asked but of writing the translation on the board when absolutely necessary in order to limit excessive and automatic use of the mother tongue in class).
The mother tongue is also particularly effective with younger learners and adult learners at beginner level to check instructions, to ensure that concepts have been correctly understood and for general classroom management. In the case of concept checking, for example, if the teacher has just been presenting the difference in concept between present perfect and past simple as in 'John has gone to Paris' and 'John went to Paris', asking the class to give a quick translation into the mother tongue will enable the teacher to be absolutely sure that the concepts have been understood. What is more, there is empirical evidence that certain areas of grammar are more amenable to explicit instruction: some things just can't be learned inductively. A number of experimental groups of 'immersion' students appear to attain high levels of functional competence yet continue to experience considerable and persistent morphological and syntactic difficulties even after several years of exposure to the target language.
Perhaps the greatest potential advantage of a knowledge of the mother tongue of the learners, however, is that it enables the teacher to contrast the language with English and to know which structures are difficult and, possibly even more importantly, which structures are easy and need very little attention. The teacher with a knowledge of the mother tongue is also in a position to know potential problems with vocabulary items - false friends, words easily confused, words with no equivalents and so on.
Finally, some learners need the security of the mother tongue. They may be the type of learner that needs to relate concepts in English to equivalents in their native language. This may be their most effective way of learning vocabulary. They may also feel that having a mother tongue equivalent is a far more efficient way of arriving at meaning than a constant process of working things out.
