Plain form + かどうか

[Whether or Not]

Connection: Plain form + かどうか

This pattern embeds a yes/no question into a sentence, meaning "whether (or not)." It follows verbs, adjectives, and nouns in their plain forms.

Connection patterns:

• Verb: 行くかどうか (whether [I] will go or not)
• i-Adjective: 高いかどうか (whether it's expensive or not)
• na-Adjective: 便利かどうか (whether it's convenient or not)
• Noun: 学生かどうか (whether [someone] is a student or not)

Common verbs used with かどうか: 分かる (know), 知る (know), 決める (decide), 考える (think about), 聞く (ask), 確認する (confirm).

Comparison: For wh-questions (who, what, where, etc.), use 疑問詞 + か instead: 何を買うか分かりません (I don't know what to buy).

Examples:

彼が来るかどうか分かりません。(I don't know whether he will come or not.)

明日雨が降るかどうか、天気予報を見ました。(I checked the weather forecast to see whether it will rain tomorrow or not.)

この店が安いかどうか、調べてください。(Please check whether this shop is cheap or not.)