To forget means to fail to remember a fact, name, or piece of information; to stop thinking about something deliberately; or to leave an item somewhere by accident. It is an irregular verb: forget → forgot → forgotten.
What Does Forget Mean?
Forget comes from Old English forgietan, built from the prefix for- (expressing loss or removal) and gietan (to grasp or seize). The root idea is literally to lose one's mental grip on something. Related words include German vergessen and Dutch vergeten, all from the same Germanic base. The word has been in continuous use in English since before the Norman Conquest.
In modern British English, forget covers three main senses. First, the cognitive sense: failing to recall information stored in memory ("I forgot his name"). Second, the intentional sense: choosing to put something out of one's mind ("Try to forget about the argument"). Third, the accidental sense: leaving an object behind ("She forgot her umbrella"). Each sense is extremely common at all levels of English, making forget an essential word for learners.
One of the most important grammar points for learners is the contrast between forget + to-infinitive (failing to do something) and forget + gerund (losing the memory of a past event). Mastering this contrast will immediately improve both your writing and your speaking accuracy.
Example Sentences by Level
| Sentence | Level | Usage note |
|---|---|---|
| I forgot my bag at school. | A2 | accidental sense; past simple irregular form |
| Do not forget to include a conclusion in your written assignment. | B1 | forget + to-infinitive (obligation to do something) |
| She had completely forgotten that the meeting was moved to Thursday. | B1 | past perfect; adverb intensifier "completely" |
| Moving abroad was an experience he would never forget, no matter how many years passed. | B2 | forget + gerund implied; conditional clause; emphatic negative |
| It would be remiss of any policymaker to forget the long-term environmental consequences of rapid urbanisation. | C1 | formal written register; "remiss to forget" fixed phrase |
Collocations
| Collocation | Example in context |
|---|---|
| completely forget | I completely forgot about the dentist appointment. |
| totally forget | Sorry — I totally forgot you were coming today. |
| forget all about | Once the holidays started, she forgot all about her worries. |
| hard to forget | The smell of that bakery was hard to forget. |
| easy to forget | It is easy to forget how much progress we have made. |
| never forget | I will never forget the kindness of those volunteers. |
| forget in a hurry | That performance was not one you would forget in a hurry. |
| forget momentarily | He forgot momentarily where he had put his glasses. |
| forget the past | The therapist encouraged her to forget the past and focus on the present. |
| forgive and forget | After the argument, they decided it was best to forgive and forget. |
Usage Notes
Gerund vs. Infinitive After Forget
Forget + to-infinitive — means failing to do something (the action is in the future or was due to happen):
“Don’t forget to lock the door before you leave.”
Forget + gerund (-ing) — means losing the memory of a past action:
“I’ll never forget visiting the Highlands for the first time.”
This is exactly parallel to remember: “Remember to post the letter” (future task) vs. “I remember posting the letter” (past memory). Both verb pairs are core B1–B2 grammar points in British English syllabuses.
Common Mistakes
Watch Out For
I forgot my keys on the bus.
I left my keys on the bus. (Use leave when naming the location — this is standard British English usage.)
She has forgot to reply to the email.
She has forgotten to reply to the email. (Past participle in British English is forgotten, not forgot.)
Don’t forget doing your homework.
Don’t forget to do your homework. (A future obligation uses forget + to-infinitive.)
Related Words
Synonyms & Antonyms
Synonyms (to fail to remember):
Antonyms: