Stack Overflow gets a good daily chunk of questions posted by non-English speaking users. They, part of the time, post questions that are valid but are poorly formed for English speaking users. As a result they are difficult to fully understand and they get down-voted pretty often.
Sometimes, if I can't update the OP and reformat the question to be more clear I'll start asking questions to the OP to help determine what the problem is. However, by then it's got -5 votes and going to get closed pretty fast.
I know the forum mods and users on Stack Overflow deal with these accordingly and correctly, but sometimes I would still like to help because I believe I can.
What's the best practical way to deal with these situations?