Translation guide
This guide covers how to express forgetting in Japanese, from simple memory lapses to leaving things behind and intentional disregard.
Express that you cannot remember something or have forgotten information.
The most common verb for forgetting. Transitive, so it takes を. Can be used for facts, names, events, etc.
Literally 'cannot recall'. Used when you are trying to remember but can't. Emphasizes the inability to retrieve the memory.
あの映画のタイトルが思い出せない。
I can't remember the title of that movie.
A colloquial term for a temporary lapse of memory, like 'brain fart'. Often used for forgetting something you should know.
彼の名前、ど忘れしちゃった。
I totally blanked on his name.
Express that you accidentally left an item somewhere.
Also used for leaving things behind. The location is marked with に or で.
電車に傘を忘れた。
I left my umbrella on the train.
家に財布を忘れてきた。
I left my wallet at home.
Specifically means to leave something behind by putting it down and forgetting it. More precise than 忘れる.
Express that you failed to perform an intended action.
Standard pattern: verb plain form + のを忘れる. The の nominalizes the verb.
鍵をかけるのを忘れた。
I forgot to lock the door.
牛乳を買うのを忘れないで。
Don't forget to buy milk.
A slightly formal/written way to say 'without forgetting to do'. Often used in instructions.
書類を提出するのを忘れずに。
Be sure not to forget to submit the documents.
Express intentionally disregarding or moving on from something.
Can also mean to put something out of your mind, often with もう (already) or in imperative form.
もうあのことは忘れよう。
Let's forget about that.
嫌なことは早く忘れたい。
I want to forget unpleasant things quickly.
Literally 'don't mind'. Used to tell someone not to worry about something, effectively 'forget about it'.
失敗は気にしないで。
Don't worry about the mistake. / Forget about the failure.
Idiom meaning 'let bygones be bygones', literally 'let it flow away in the water'. Used for forgiving and forgetting past issues.
Express that something is no longer remembered by people.
Passive form of 忘れる. Used when something is forgotten by people.
その事件は人々に忘れられた。
That incident was forgotten by people.
Literally 'weathering', used metaphorically for memories fading over time. Often used for historical events.
戦争の記憶が風化しつつある。
Memories of the war are fading.
English uses 'forget' for both memory and leaving items. Japanese uses 忘れる for both, but context and particles differ. For leaving, use location に/で + object を忘れる.
忘れる is general forgetting. 思い出せない specifically means you are trying to recall but can't. Use 思い出せない when the memory is on the tip of your tongue.
カフェにスマホを置き忘れた。
I left my smartphone at the cafe.
過去のことは水に流そう。
Let's let bygones be bygones.