A lot of Chinese parents believe that kids need to learn a foreign language - generally English - as early as possible, so they spend a huge amount of money to get their children into "training centers" at just two or three years old. As a recent Guangming Daily piece collected, online comments on early childhood instruction are very mixed.
One of the big drawbacks is that it takes time away from native language learning, resulting in kids being relatively slow in picking up Chinese words and especially characters. And unless the foreign language is kept up, it easily fades from children's memories over time.
But, argued others, learning a foreign language is good for the soul, just like music and sports, and helps kids develop into better people all-round. Early language training can also take advantage of children's natural facility with languages, and improve their cognitive abilities across the board. Picking up another tongue early on is also by far the best way to acquire true fluency, and especially a native accent, in the long run.