You don't need to brush up on your English skills if you hire me, I'm a freelancer specializing in polishing up non-native English speaking companies' website and promotional copy when they're expanding into English-speaking markets.
From my website (which I won't post here out of integrity, despite the sales pitch): "I comb all English language copy on your website, printed advertising , billboards, even television and radio spots, before going to press.
I produce a report that identifies and corrects all spelling, grammatical, and phrasing/punctuation errors that may have been missed during the initial translation to English.
My background is in both formal and conversational English, with a long history of writing both fiction and academic pieces. I am able to work with clients to modify the tone and context of wording in your message, to better match the original meaning and intent."