In English Language Learner, people answer questions referring to English by English.
Analogue to this, can I answer questions in the site by Chinese?
I think we should allow both questions and answers in both English and Chinese.
I know I wasn't here when the site was proposed so I'm not sure what the original idea was. But I was active on the early Spanish site and they wanted to cater both to Spanish learners via English and Spanish speakers who wanted to learn more about their language, much like on English Language & Usage.
I'm no longer active on Spanish but at one point we decided it was OK to ask or answer in either language and we would welcome contributors' edits to provide translations into the other language in such posts.
The way we did at was simply to add a horizontal divide at the bottom of the question or answer with
--- so it would divide it into two halves. In the second half you would translate as accurately as you could without changing the formatting or anything else in the original question.