If you’re going to find more money through niche, but if your language not so good. What’s your solution? 
Improve your lingual skills (obviously), there’s no niche or industry in the world that will take you seriously if you can’t speak or write in the language it serves.
This thread should be titled “Spelling Error” or “Typo”
Get hold of a quality spell and grammar checker and if you wish doing the work to get done by others, then you can hire someone to proof read the documents and identify grammatical errors alongside spelling errors.
hire someone whose language is good