You don't use the simple past with have or had to form the perfect tenses. Forgotten is the past participle: "The waiter has forgotten us/ had forgotten us." You use the past participle to form the perfect tenses.
How do you use forgotten in a sentence?
Forgotten sentence example
- Yeah, I'd forgotten about that. ...
- She glanced at the door, realizing she had forgotten to lock it. ...
- In a few minutes they had forgotten about the birds. ...
- Someone must have forgotten something. ...
- I expect he has forgotten me.
Is forgotten the past tense of forget?
The past tense of forget is forgot (archaic) or forgat (obsolete). The third-person singular simple present indicative form of forget is forgets. The present participle of forget is forgetting. The past participle of forget is forgotten or forgot (archaic).
