Nowadays, more and more parents prefer to let their children learn second language in early childhood because they believe that foreign language learning is the sooner the better. Many children are sent to language classes and spend lots of time on learning. Some critics argue that this behavior deprives children’s happiness of childhood and people still can learn language as quickly as children. However, in reality, adults cannot acquire language just as effectively as children because children’s brains are more flexible for language learning and have more time to spend on study. First, comparing with adults’, children’s brains are more flexible to learn languages. Some people believe if children learn other languages at the same time they learn first languages, their abilities of foreign languages will just as well as first languages. It has been found that children’s brains normally format themselves accurately from birth until puberty. If children learn a second language in that period, their ability of this language will get better (Foust 1). Children’s brains are also adaptive to learn more than one language at same time. Susan Curtiss, UCLA Linguistics professor claims that “The power to learn a language is so great in the young child that it’s seem to matter how many languages you seem to throw their wayChildren just have this capacity. Their brain is ripe to do thisthere doesn’t seem to be any detriment to develop several language at the same time” (3). Therefore, it is better for people to learn languages at young age because their brains can learn new things quicker and easier at that time. Furthermore, it is cleared that children can spend more time on study than adults. There’s a study found that students who spend more time on language learning, students who join intensive programs and students who use the target language more often will require new languages better than others (qtd. in Curtain 108