Embedding a Yes/No Question
かどうか takes a yes-or-no question and tucks it inside a larger sentence.
- 来るかどうか分かりません。(I don't know whether he's coming.)
Literally "whether or how" — か marks the question, どうか stands in for the alternative.
Formation
Plain form, and drop だ:
| Type | + かどうか |
|---|---|
| Verb | 来るかどうか |
| い-adjective | 高いかどうか |
| な-adjective | 元気かどうか |
| Noun | 学生かどうか |
With a Question Word, Drop どうか
If the embedded question has 何, 誰, どこ and so on, it is no longer yes/no — use か alone:
- ○ 何が起きたか分かりません。(I don't know what happened.)
- × 何が起きたかどうか分かりません。
That is the rule worth remembering: かどうか for yes/no, か for wh-questions.
Verbs That Follow It
Typically verbs of knowing, checking or being unsure:
- 分からない (don't know)
- 知らない (don't know)
- 確かめる (check)
- 覚えていない (don't remember)
- 心配だ (be worried)
The Casual Shortcut
In speech, どうか often drops even in yes/no questions:
- 来るか分からない。(Not sure if he's coming.)
Both are correct; かどうか is clearer.