I think the way to go is **flag/vote to close as unclear what you're asking**, like [SO does it](https://meta.stackoverflow.com/questions/297673/how-do-i-deal-with-non-english-content).

If you see any chance you can translate the post properly, an edit (suggestion) is welcome, but in my opinion in general providing the question in English is **one of OP's duties**. Translation is even frowned upon by some, see the above linked question. A question that most of the site's users can't understand is the very definition of *unclear*, and closing a question gives OP the chance to correct it. Jeff Atwood himself wrote in his blog post [Non-English Question Policy](https://stackoverflow.blog/2009/07/23/non-english-question-policy/):

> If the post has salvageable English and makes some modicum of sense, it should be edited and improved just like any other post. If it does not, it should be closed.

More about why English was chosen can be read on [meta.SE: Do posts have to be in English on Stack Exchange?](https://meta.stackexchange.com/questions/13676/do-posts-have-to-be-in-english-on-stack-exchange) – there are sites in the network that allow other languages, but AU is none of them.