Chinese Grammar- Interrogatory

Questions can be identified in oral and in written Mandarin, can often be identified with the particle "ma". Often these are questions that require a yes or no.

For example:

Ni mai kele ma?

Do you sell coca cola?

I'm familiar with this pattern; Japanese uses the particle "ka" to indicate a question. The difference, is that they use it for all questions, not just ones for a yes or no answer. Unlike in Japanese though, it disappears in a sentence if you ask a question with "when" or "how" "how many" etc.. It is only good for yes or no questions? So much for knowing if people are asking you a question or making a statement, just by listening for one word!