hanamaru
How to ask a question
か at the end turns any sentence into a question; the word order does not change. The question word stands where the answer will stand.
Example Sentences
What is this?
Who is he?
A yes/no question is the same sentence with か at the end: がくせいです — がくせいですか. Nothing changes place, nothing is added in the middle. The answer is はい or いいえ, ideally with the whole sentence after it: いいえ、がくせいじゃありません.
To ask what, who, where or when, put a question word where the answer will stand. なに/なん is what: それは なんですか. だれ is who: だれの ほんですか. どこ is where: ねこは どこに いますか. いつ is when: いつ かえりますか. いくら is how much, どう is how: おちゃは どうですか. どれ and どちら are which. The question word takes the same particle the answer takes: だれが いますか — ゆきさんが います.
Among friends か often drops, and the question is heard in the rising tone at the end: なに する？ Politely you keep か.
More question forms have pages of their own: asking whether something is okay (ても いいですか) and how to get somewhere (どうやって).