interrogative sentences structure, question words

[indre]

I've a problem with making interrogative sentences. I know that if we needn't to use question words such as 谁，哪， 什么 and etc., we have to put 吗 at the end of interrogative sentence. But if I need to use 谁，哪， 什么 and etc.. what is the correct order of interrogative sentences? Have these questions words to be put at the beginning, in the middle of sentence or at the end?

[jasoninchina]

They are typically put at the end of the sentence.

你是谁？

这是什么？

你去哪儿？

Occasionally, you may say something like

谁是你们的中文老师？

谁走了？

But remember, you would never say

谁是你？

[AdamD]

My understanding is that the question word can go in place of the word/phrase that would be in the sentence if it were a statement and not a question. So:

你去饭店吃叉烧包。

...would become:

你去哪儿吃叉烧包？

Note that there's no 吗 because there's a 哪儿.

If this is wrong or off the mark, I'll edit the post accordingly.

[Daan]

Yes, it's exactly as Vzzzbx said: the question word replaces the phrase it is supposed to question. So Mandarin is unlike English, where question words are generally at the beginning of a sentence. Some more examples can be found here. Don't hesitate to ask, though, if you still have questions after reading that

[Silent]

Have a look at this:

http://www.clearchinese.com/videos/2011/01/16/forming-content-questions/

[indre]

Thanks for all of you! Finally i am capable to make interrogative sentences correctly