In a previous article I discussed the myth that young children are the best second language learners. In fact, studies have shown that adolescents and adults are in many ways better at learning a new language than children, except in the area of pronunciation. This is probably because they are already literate in their first language and can use some of their knowledge about language and language learning when learning the second language. However, this doesn't answer the important question: What's the best age to learn a new language? This question, like most about language learning, cannot be answered so simply. It depends on the situation.
For example, a child who is born to an American father and German mother living in the USA can start to learn both German and English from the moment he is born. This is probably the most favourable situation for anyone who wishes to speak two languages fluently as an adult. A child of school age who emigrates to the USA has no choice, and must start to learn the new language, English, as soon as she arrives. Depending on the age of the child, it can take up several years for her to reach the level of a native English speaker. It is important in this time that she continues her first language development. And it is equally important that she, her parents and her teachers do not have unrealistic expectations about how easy learning will be and how quickly it will happen.
The two situations described above contrast with situations where there is more choice over whether and when the second language is introduced. Either the choice is made by the education authorities in the area where the child lives, or parents can decide on an individual basis whether to enrol their child in a foreign language learning program. It is this last situation that I wish to discuss a little further.
Some specialists in language acquisition claim that the sooner a child starts to learn a second language the better. It certainly seems to make sense that the earlier you start, the longer you will have to learn, and the more progress you will make compared with someone who started later. However, there is evidence that this is not the case, particularly if the second language comes to take the place of the first language, which has never been allowed to develop properly. One researcher* talks of the dangers of double semi-lingualism for early learners of a second language; i.e. the child does not develop full proficiency in either of the two languages. And as mentioned above, it has been found that older learners of a language are more efficient learners, so they may need less time to reach the same level of proficiency as younger learners. Also, of course, if more time is spent learning a second language during the school day, then some other subject must be cut or reduced to make way for it. This may not be desirable.
So what is the best age for a person to start learning a foreign language in situations where there is a choice, and where it is not critical that a native-speaker-like pronunciation is acquired? The answer, according to current research, is early adolescence, so about 11-13. And the more motivated the child is to learn the new language, the more successful he will be!
* Scovel T, 1999 The younger the better myth and bilingual education In: Gonzalez, R (ed.) Language Ideologies: Critical Perspectives Urbana, IL: NCTE