As a native Russian I know Russian perfect - it's my weapon. But inspite of I know English not to bad, i would never write any long article say about Nabokov or about Almodovar films. for now of course.

I can share a lot of information which I learned for while my life, but I don't have enough blocks-words just to write-write-write without breaks for checking a word in a dictionary or rewriting all sentence because of wrong words order.

For writing really well you need to think on the language