Translation guide
Expressing that someone did not manage to do something, missed doing it, or ended up not doing it. Japanese uses various verb endings, compound verbs, and set phrases rather than a single word for 'fail to do'.
Expressing that the action was attempted but not successfully completed, or that circumstances prevented it.
Attach to the stem of a verb to mean 'fail to V', 'miss V-ing', or 'almost V but didn't'. Often implies a mistake or missing an opportunity.
電車に乗りそこなった。
I failed to catch the train.
彼の名前を聞きそこなった。
I missed hearing his name.
Similar to そこなう, but slightly more formal or written. Means 'fail to V' or 'miss the chance to V'.
大事な書類を送り損ねた。
I failed to send the important documents.
Literally 'forget to V', but often used for 'fail to do' when the failure is due to forgetting.
宿題をするのを忘れた。
I forgot to do my homework. / I failed to do my homework.
Used to say 'I thought I had V-ed, but actually I hadn't'. Implies a failure to realize the action was not done.
鍵をかけたつもりが、かけていなかった。
I thought I had locked the door, but I hadn't.
Expressing that the action was intended but ultimately not carried out, often due to circumstances or procrastination.
Means 'without doing V'. Often used when something ended without the action happening. ことなく is more formal; ずに is common in speech.
彼は何も言わずに去った。
He left without saying anything.
一度も使うことなく捨てた。
I threw it away without ever using it.
Formal expression meaning 'did not reach the point of V-ing'. Used in reports or formal explanations.
合意に至らなかった。
We failed to reach an agreement.
Using 結局 (in the end) with a negative verb implies that despite intentions, the action was not done.
結局、彼に会えなかった。
In the end, I failed to meet him.
Expressing that someone should have done something but didn't, often implying negligence or oversight.
Means 'neglect to V' or 'fail to V' with a nuance of shirking responsibility.
彼は報告するのを怠った。
He failed to report (neglected to report).
Means 'miss the chance to V' or 'fail to V' due to hesitation or missing the timing. Casual.
言いそびれてしまった。
I failed to say it (missed the chance).
Used in rules, contracts, or formal statements where an obligation was not met.
Formal version of 怠る, often used in legal or official contexts.
安全確認をすることを怠った。
They failed to perform safety checks.
Literally 'did not fulfill the obligation to V'. Very formal.
彼は納税の義務を果たさなかった。
He failed to fulfill his tax obligations.
The verb 失敗する means 'to fail' as in 'to make a mistake' or 'to be unsuccessful', but it cannot be directly combined with another verb to mean 'fail to do'. Saying 「Vするのを失敗した」 is unnatural. Use the compound verbs or patterns above instead.
そこなう is general 'fail to do/miss doing'. そびれる emphasizes missing the timing or opportunity. 忘れる is specifically 'forget to do'. Choose based on the reason for the failure.