Grammar
N4 connective

Whether or not 〜かどうか

Meaning

Embeds a yes/no question inside a bigger sentence — "whether ~ (or not)".

Formation

Notes

A noun or na-adjective loses its だ before か: ×学生だかどうか. The main verb is usually 分かる, 知る, 覚えている or 調べる. When the embedded question has a question WORD, use 〜か alone instead — 何時に来るか分かりません, not ×何時に来るかどうか.

Examples

I don't know whether Tanaka is coming or not.

Breakdown
Tanaka will come whether or not don't know

Please check whether this shop is open.

Breakdown
this shop is open whether please check

Do you know whether he is a student? (noun drops だ)

Breakdown
he is a student whether do you know?

I'll check once more whether it's correct.

Breakdown
correct whether once more will confirm

I'm worried about whether we'll make it in time.

Breakdown
be in time whether am worried

⚠️ Often confused with

Embedded question 疑問詞+か

Embeds a question containing WHO, WHAT, WHERE, WHEN, WHY or HOW inside a larger sentence.