I have a question from language learners...?

Try to "hear" yourself when you speak. By this I mean when you write, you write better than when you speak, as you say, so try to speak in the same way you write: speak (read out loud) what you write, this should help, at least with English. I also took about 4 years to master it completely (grammar, spelling, structure). It takes time and patience, but it'll come the more you practice speaking proper grammar, trust me.