you can talk with some foreign people
and also always use English when you talk, speak, think, etc.
I think everyone can use it very well, just have no chance to use
Someone in forum mentioned the way to learn English is simply to read, listen and talk everyday. It sounds simple but actually not. The challenge is how to persist and be the habit. I believe 90 percent guys give up because of various of excuses, such as busy work, family time etc.
Here i suggest you to choose a foreign company to work with and that will force you to learn English.