English has grammar that can't be directly translated, how did foreigners learn English as children?

Any language has grammar, it's just that most native speakers don't notice it.

The British would also like to think that in English, if you want to ask "how do foreigners learn to speak before they go to school", you can just say "How do foreigners learn to speak before they go to school? In English, if we want to ask "How do foreigners learn to speak before they go to school", we just say "How do foreigners learn to speak before they go to school", but Chinese people have to put "before they go to school" in front of "learn to speak", which is really hard to understand in this kind of grammar! Isn't it logical to say "before going to school"? How come Chinese people can say "before they went to school" and convey the same meaning? Hey, you have to learn so much grammar to learn Chinese! I don't know how the Chinese learned it! Do you understand?