What is language for? Some people seem to think it's for practicing grammar rules and learning lists of words -- the longer the lists, the better. That's wrong. Language is for the exchange   of ideas and information. It's meaningless to know all about a language if you can't use it freely. Many students I have met know hundreds of grammar rules, but they can't speak correctly or fluently . They are afraid of making mistakes. One shouldn't be afraid of making mistakes when speaking a foreign language.  Native speakers often make mistakes and break rules, too. Bernard Shaw once wrote, "Foreigners often speak English too correctly." But the mistakes that native speakers make are different from those that Chinese students make. They are English mistakes in the English language. And if enough native speakers break a rule, it is no longer a rule. What used to be wrong becomes right. People not only make history, but they also make language. But people can only make their own language. They can't make another people's language. So Chinese students of English should pay attention to grammar, but they shouldn't overdo it. When they learn a foreign language, they should put communication first. Foreigners often speak English too correctly. The sentence means that   _  .
foreigners speak correct English. foreigners speak incorrect English. foreigners speak English according to the grammar rules. foreigners never make mistakes when they speak English.