Translation guide
Expresses the idea of not perceiving or becoming aware of something, often unintentionally. Japanese uses various verbs and expressions depending on whether the failure is visual, mental, or due to inattention.
To fail to visually notice or become aware of something in one's environment.
Literally 'overlook' or 'miss seeing'. Used when you fail to notice something because you didn't look carefully enough or it was easy to miss.
重要な間違いを見落とした。
I failed to notice an important mistake.
The most general way to say 'not notice' or 'not realize'. Covers both visual and mental awareness.
彼が部屋に入ってきたのに気づかなかった。
I didn't notice him come into the room.
Similar to 見落とす, but often implies letting something pass without proper attention, sometimes deliberately.
小さなミスをうっかり見過ごしてしまった。
I carelessly failed to notice a small mistake.
Literally 'doesn't enter the eye'. Used when something is in your field of vision but you don't register it, often because you're focused elsewhere.
看板が目に入らなかった。
I didn't notice the sign (even though it was there).
To not mentally grasp or understand a situation, fact, or change.
Again the most common choice. Works for both physical and abstract noticing.
彼女が怒っていることに気づかなかった。
I failed to notice that she was angry.
To realize or become aware of something, often with a nuance of finally understanding. In negative form, it means failing to grasp the truth.
彼は自分が騙されていることに悟らなかった。
He failed to notice that he was being deceived.
To sense or infer something from subtle cues. In negative, it means failing to pick up on hints or atmosphere.
To miss something because you were not paying attention or were preoccupied.
Combines 'carelessly' with 'miss seeing'. Emphasizes the accidental nature of the failure.
うっかり約束の時間を見逃した。
I carelessly failed to notice the appointment time.
Literally 'spacing out and not noticing'. Used when you're daydreaming or not focused.
ぼんやりしていて信号が赤になったのに気づかなかった。
I was spacing out and failed to notice the light turned red.
Specifically for failing to hear or catch something said. 'Miss hearing'.
見落とす is purely visual and accidental. 見過ごす can be accidental or intentional (overlooking a fault). 気づかない is the broadest, covering any failure to notice or realize.
誤字を見落とした。
I missed a typo (didn't see it).
彼の無礼を見過ごすわけにはいかない。
I can't overlook his rudeness (intentional).
異変に気づかなかった。
I didn't notice the anomaly.
Avoid directly translating 'fail to notice' as 気づくことに失敗する. It is unnatural. Use the verbs and phrases above instead.
彼の気持ちを察することができなかった。
I failed to notice his feelings (couldn't read between the lines).
大事なアナウンスを聞き逃した。
I failed to notice the important announcement (didn't hear it).