There is a physiological factor in there somewhere. Children who have been denied the opportunity to learn language up to about the age of seven seem not to be able to learn to speak after that, even in a first language.
However, that doesn't mean adults can't learn to speak another language and be mistaken for a native speaker. The neural pathways required are probably there from the first language. Anyone can learn not to have an accent. Actors do it all the time. Vocabulary is just a matter of usage and rote. Grammar is also learned by usage and rote. Given time and natural ability, many people master a second language as an adult.
But, like I said before, it depends on a variety of factors, and may not be true (or as true) for every language. It is highly unlikely someone going from English to Vietnamese as an old age adult is going to be able to become like a native speaker. But learning a language close to yours (such as Dutch to German, or Spanish to Italian) is relatively easy. Languages that are completely phonetic like Spanish are easy, languages that are not (like English) are harder. Some languages are also inherently more difficult than others, either because they are unique (like Finnish) or just weird (like Xhosa) or have huge vocabularies (like Australian Aboriginal languages) or use tones like Mandarin (which makes it harder for an older person simply because of hearing loss!), or have more exceptions to rules than rules (like English).
Last edited by The Pook; 02/24/08 10:40 PM.
