Questions with か

Questions in are formed with tone of voice, and they sometimes end with か or の also depending on the politeness level.

This lesson will cover yes/no questions with か. We'll cover "wh"-questions and の questions later.

When reading written language, where tone does not come across, writers often indicate the presence of a question with a question mark ？ just like in English. However, be aware that this is not required as questions can also end with just か (or even の) and a period 。 without the question mark. Japanese does not have the same punctuation rules as English.

暑い？
Is it hot? (casual)

暑いですか。
Is it hot? (polite)

When a question is formed with か, the か just goes at the end of the sentence. However, か to ask questions is normally reserved for the polite form (ですか？ and ますか？). In casual form you don’t usually ask questions ending with か as it can sound very stark and too direct. People just use a rising tone of voice like in the example above.

There are situations where か can be used in casual form too, but they are usually rhetorical questions, or have a specific type of nuance that is hard to explain in a beginner guide. Just don’t fall for the trap of asking every question by just slapping か at the end, at least until you really know what you’re doing.

This last piece of advice however does not apply to fictional language used in media and is one of the most common sources of disconnect between real life Japanese and fictional Japanese (anime, manga, books, etc).

お前は警察か
Are you with the police? (sounds aggressive, fictional language)

As shown above, to ask a か question in polite language, just add か after です/ます

彼は学生ですか。
Is he a student?

古いですか
Is it old?

食べますか
Will you eat?

There are some set phrases and expressions that may use か to ask what seems to be rhetorical questions, but they aren’t actually questions. For example:

あ、そっか。
Ah, I see.

そっか is a casual slurring of そうか, literally “Is that so?”