How to ask what, who, where, and how much.

• なに / なんwhatこれはなんですか = What is this?
• だれwhoあのひとはだれですか = Who is that person?
• どこwhereトイレはどこですか = Where is the toilet?
• いつwhenいつきますか = When are you coming?
• どうしてwhyどうしていきませんか = Why aren’t you going?
• いくらhow much (price)これはいくらですか = How much is this?
• どうhow (manner / opinion)にほんはどうですか = How is Japan?
• どのwhich (+ noun)どのほんですか = Which book is it?
• どれwhich one (standalone)どれがいいですか = Which one is good?
• いくつhow many; how oldみかんはいくつですか = How many oranges?
• なぜ (naze)why (more formal than どうして)なぜですか = Why is that?
• どちら (dochira)which of two; where/which (polite)おくにはどちらですか = Where are you from?
• なんじ (nanji)what timeいまなんじですか = What time is it now?
• なんにん (nannin)how many peopleなんにんいますか = How many people are there?
• なにか (nanika)something / anythingなにかたべますか = Will you eat anything?
• だれか (dareka)someone / anyoneだれかいますか = Is anyone there?