How about putting "Language" in like location under user profile details?

Location does not always indicate what languages one is fluent in.

I'm probably more lenient with noobies struggling to ask questions when they let us know their native language is not Americanized English (AE).

This is one of the more international forums I visit and I'm constantly amazed at the world wide participation on an AE forum.
Excuse my English.

I think the international spread on this board is quite common to what I see most places. Many people are reasonably good at writing English (AE or E or a mix..), so maybe it's not so visible. It's IMHO a good idea to start out with the assumption that maybe the writer's native language isn't English, until proved otherwise..