There is a critical period during childhood where you acquire anything a lot easier than in adulthood. Starting from birth until approximately seven years, intense building of new synaptic connections and pruning take place. During pruning, synaptic connections that are effective and useful strengthen, and ineffective and useless ones are eliminated. That is why it is called pruning. This process helps you learn anything very effectively; that is why it is said that if you start learning a language during this critical period, you can reach a native-like level of language. However, adults also can reach a native-like level of language in some aspects; only the process will require more conscious efforts. In childhood it is rather an unconscious, natural process. When a child is exposed to an environment, he or she will soak up everything like a sponge. It will come just naturally to him or her during this critical period.