Forgot vs I don't remember what he said

When to use each in English, with meaning, register, and examples.

Forgot

Top 1,000 (very common)

I don't remember what he said

Top 1,000 (very common)

	Forgot	I don't remember what he said
Pronunciation	🇬🇧 //fəˈɡɒt// 🇺🇸 //fərˈɡɑt//	🇬🇧 //aɪ doʊnt rɪˈmɛmbər wɒt hiː sɛd// 🇺🇸 //aɪ doʊnt rɪˈmɛm.bɚ wɒt hi sɛd//
Meaning	To fail to remember something.	I can't recall his words.
Example	I forgot my wallet at home.	In the meeting, I said, 'I don't remember what he said.'
Register	Neutral	Neutral
How common	Top 1,000 (very common)	Top 1,000 (very common)
Collocations	forget someone's name, forget a lesson, forget an appointment	remember what, what he said, don't remember, remember clearly, forget completely
Antonyms	remember, recall	remember, recollect, retain
Common mistakes	Confusing 'forgot' with 'forget'. 'Forgot' is past tense., Using 'forgot' without an object when it needs one., Mispronouncing the word, especially the ending.	Saying 'I not remember' instead of 'I don't remember'., Confusing 'remember' with 'remind'., Using it in a context where one should provide a specific answer.
Usage notes	Commonly used in everyday conversation. Avoid using in very formal writing. More often used in past tense.	Use this phrase to express forgetfulness about someone’s words. It's appropriate in casual and formal settings but avoid in very serious contexts where a precise recollection is expected.

See it in real clips

The Pitt › S1 E1

I forgot to take my damn enalapril this morning.

Ted Lasso › S1 E1

Ah, no, I-I forgot.

Breaking Bad › S1 E5

we forgot our IDs, and we were wondering

The Pitt › S1 E1

I forgot to take my damn enalapril this morning.

Ted Lasso › S1 E1

Ah, no, I-I forgot.

Forgot

Look, I don't remember what he said, but I don't see how he could have run to the door.

I don't remember what he said

Frequently asked questions: Forgot vs I don't remember what he said

What's the difference between Forgot and I don't remember what he said?

Forgot: To fail to remember something. I don't remember what he said: I can't recall his words.

Can you show an example of each?

Forgot: I forgot my wallet at home. I don't remember what he said: In the meeting, I said, 'I don't remember what he said.'

Can I use Forgot and I don't remember what he said interchangeably?

Not always. Forgot and I don't remember what he said are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.