The acquisition of a second language.

It is claimed that if children can begin to acquire a second language at an early age they will find it easier to develop fluency, and will speak it without an accent. Age is a factor in acquiring one's mother tongue, and this also applies when learning a second language. One essential to developing such a skill is the ability to switch from one language to the other, as appropriate. Studies on the effects of age on this learning are reviewed. Techniques such as positron emission tomography can now be used to show which areas of the brain are involved in developing new skills, and much has been learnt in this way. Differences can be demonstrated between the cerebral function of the children who learn a second language at an early age and those who do this when they are older, and also between those who acquire a high degree of fluency and those who never do. If children speak a second language by hearing it in the environment in which they live, they are acquiring it as they do their mother tongue, but if they start at the age of 12 years they are learning it like any other subject they study. If the opportunity is present, surely it is better to acquire a second language than learn it.