First of all, according to scientists, children in the age of studying in kindergarten are very clear of mine, easy to learn new things and imitate foreign people's voice. These are very useful in learning foreign language. As a result of this will lead to their pronunciation like native speakers when they grow up.
In addition, if children stat to learn foreign language in kindergarten, they will have a plenty of time to practice and become more fluency. In fact, the popularity of using the Internet, broadcasting foreign TV channels and expanding the tourism have given children much more a chance to practice with the time. Besides, adults tend to be afraid of making grammatical mistakes when they speak, therefore they have a tendency to ashamed to speak in public. But children do not worry about that, because they just repeat day by day words and sentences which they hear from their teachers and native speakers.
I think that children should begin to learn a foreign language as soon as they start school. Even many parents taught their children the foreign language before elementary school. It is obvious that really necessary.
People can learn a language easily when they are young. Many older people often say that they are too old to learn a foreign language. They can't remember the words or phrases even after hundreds of times reciting. It's hard for them in faith, but while it's quite different from the young. A healthy child has a better and quicker memory, so the new things he learned may not be...