How to improve it?

the pronunciation of Chinese is a little rigid, if you are nervouse with communaction, don't take more attention to grammar, the system of Chinese is too complex, you may remember more words first, and during talking and daily you can practise the pronunciation

I know that the way you say in Chinese is een more important that what you are saying. An improper inflection could land you in prison for years without contact with loved ones. Be careful.

I think you'd better forget the rules and try to learn as many collocations and chunks as possible. Try to imitate the people around you.

I agree. Those lexical chunks are priceless, though I'm not speaking specifically of Chinese.