I'm not sure if the Meta is the right place for sharing ideas, but I couldn't find any better one (let me know if I should have proposed it somewhere else).
What I would like to suggest is to mark questions of a low lingual quality with a common tag (for example: "poor-english"). Because you already wonder, why this might be useful, let me explain some of benefits.
Using such tag would allow it to easily find questions that need editing due to grammar mistakes. Just browse such tagged questions, edit (or rewrite them, though very carefully - but only if that is possible without changing or guessing the meaning), and remember to remove the tag after applying corrections.
If you feel a question you've just seen contains serious mistakes, but either a) do not know how to correct it b) prefer a native English speaker would fix the mistakes in it, or c) do not have time to edit it, simply mark it with the tag, and someone else will take care.
If we used such tag, even users with little reputation might mark questions, to help cleaning-up, instead of (or while?) informing moderators.
If non-moderators would be able to browse & edit questions marked as "poor-english", more users would help the mods to edit these questions.
We might also somehow suggest new users to add such tag to their question, if they feel their message may be difficult to understand (instead of writing: "i'm sorrying for mine badly englisch", or anything related).
The point in this everything? I've just noticed that there is quite a lot of questions that are never answered, because of their terrifying language. Maybe this way it would be way easier to manage grammatically incorrect questions.