か（どうか） (whether or not)

• Reading: かどうか
• Romaji: ka (dou ka)
• Formation: Plain form clause + かどうか + Main verb

Meaning

A construction used to embed a yes-no question inside a larger sentence. か（どうか） means 'whether or not' and turns a question into a noun clause that can serve as the object of verbs like 知る, 分かる, or 聞く.

When you want to report or refer to a yes-no question indirectly, you attach かどうか to the plain form of the embedded clause. The どうか part ('or not') is optional and can be omitted, leaving just か, but including どうか makes the meaning more explicit and is often preferred for clarity. The embedded clause always uses plain form (not です/ます), even when the main sentence is polite. This structure differs from embedding information questions (何, どこ, etc.), which use only か without どうか. Learners often mistakenly use polite forms inside the embedded clause or forget to drop だ before か with na-adjectives and nouns.

Examples

1. 彼が来るかどうか分かりません。 I don't know whether he will come or not.
2. この答えが正しいかどうか確認してください。 Please check whether this answer is correct.
3. 明日雨が降るかどうか天気予報を見よう。 Let's look at the weather forecast to see whether it will rain tomorrow.

Usage Guide

Context: spoken, written, everyday

Tone: explanatory

Do Say

• 試験に受かるかどうか心配です。
• 彼女が賛成するかどうか聞いてみます。
• この道で合っているかどうか不安になった。

Don't Say

• 彼が来ますかどうか分かりません。(Using polite form inside the embedded clause — must use plain form before かどうか) → 彼が来るかどうか分かりません。
• 何を買うかどうか迷っています。(Using かどうか with an information question — かどうか is only for yes-no questions) → 何を買うか迷っています。

Origin & History

This pattern combines the interrogative particle か with どうか (literally 'how,' used adverbially to mean 'or not'). The combination became standard in modern Japanese for embedding polar questions.

Cultural Context

Generation: All ages

Social background: Universal