Despite the fact that the child is still to acquire a large number of other aspects of his or her first language through the later years of childhood, it is normally assumed that,by the age of five, the child has completed the greater part of the basic language acquisition process. According to some, the child is then in a goog position to start learning a another language until much later. The question that always arises is: if first language acquisition was so straightforward and largely automatic,why is learning a second language so diffcult l? We will try to answer that question in the next chater.