か否か (ka ka)

if or if not; whether or not something is the case

Meaning & usage

か否か presents two alternatives, X or not X, and works like かどうか but with a formal, written tone. It attaches to a plain-form verb or i-adjective, to na-adjectives and nouns plus である, and to だ-ending phrases; the negative alternative is expressed by 否か itself, so no separate negative form is needed.

Example sentences 8