か

か at the end of a sentence turns it into a question. Nothing else changes: the word order stays as it was, and か goes after です or after the verb.

The voice rises on か. A question is normally written with 。 because か already marks it. ？ appears in casual writing.

Answering

The answer starts with はい (yes) or いいえ (no) and then repeats the end of the question.

English answers "Yes, I am" or "Yes, it is". Japanese cannot answer with です alone. Repeat the word in front of it, or say はい、そうです("yes, that's right").

• × はい、です → はい、学生です

With question words

A question word such as 何 (what), だれ (who), いつ (when) or どこ (where) sits where the answer will go. It does not move to the front, and か still ends the sentence.

Usage notes

These go beyond a plain yes-or-no question.

A か B – "or"

Between two nouns か means "or".

That is not how you ask someone to choose. こうひいコーヒーかおちゃお茶をのみます飲みますか asks whether they will have either one, and the answer is yes or no. To offer a choice, ask two questions in a row.

Question word + か

か straight after a question word makes it indefinite: なんか何か something, だれか someone, どこか somewhere.

A question inside a sentence

A plain-form question ending in か can sit inside a longer sentence, in front of a verb such as わかります or 知っています. The inner question does not make the whole sentence a question.

Casual speech

Among friends か is usually left off, and a rising voice does the asking. Plain form + か sounds blunt, and だ does not come before a final か: ×学生だか？ is wrong.