なに・だれ・いつ・どこ・どうして
What / who / when / where / whymachine translation
FormationPut the question word in the exact slot being asked about + か
Question words in Japanese sit right in the position of the information being asked about; the sentence order does not change, and か is added at the end: 何を食べますか "what will you eat?". なに (what), だれ (who), いつ (when), どこ (where), どうして (why).
何 is read なん before です or a counter (何ですか, 何時); otherwise it is usually read なに. いつ does not take the particle に: いつ行きますか, not いつに.
For a どうして question, you answer by stating the reason and ending with からです.
Examples
今晩何を食べますか。
What are you eating tonight?
あの人は誰ですか。
Who is that person over there?
どうして昨日来ませんでしたか。
Why didn't you come yesterday?