About English ?

For a start: "...like a native". Note "a".

Go to a school that teaches it.

It's not just YOUR English. The whole English language is strange, compared to other languages :)

You obviously know a lot of English already. Maybe your next step could be to use the internet to listen to American, British, or other English-speaking countries' radio and TV stations to get an idea of how people in those countries speak. (I'm sure you're aware that American English, British English, Indian English, Caribbean English, West African English, etc., are all quite different.)

And of course in most countries there are foreign-language schools that can teach you the colloquial way to talk in other countries for a reaonable fee. Check those out.

Good luck and welcome to the very weird world of English! :)