The phrase "someone has forgotten" is grammatically correct and can be used in written English.
It is a complete sentence and can be used in various contexts. Example: "Someone has forgotten to turn off the stove. It could be dangerous if we don't go check on it."
"One might think that it's a dog someone has forgotten in the compartment; not at all, it is M. Flaubert, groaning".
"I don't want to hear at 12 30 that day that someone has forgotten their uniforms," said Tymon, who has organized the days for 10 years.
"One might think that it's a dog someone has forgotten in the compartment; not at all, it is M. Flaubert, groaning". He preferred to stay up the night before in order to sleep through the train journey.
Falling in the toilet occasionally because someone has forgotten to put the seat down will be a small price for me to pay for taking a pass on that.
And like the tensions that continue after a drunken argument, when someone has forgotten what they said, Tim's night-time activity has turned into a nightmare and has begun to (not surprisingly) take its toll on his marriage.
In the evening, the on-site church is packed for the service: it's all big windows and bright stained glass, with the ambience of a crematorium where someone has forgotten to deliver the body.
Someone had forgotten it.
Someone had forgotten to fund the prepaid credit card that covered the bill.
It was all so brusque and low key, there was a suspicion that someone had forgotten to recharge the Arcola batteries.
Was it a placeholder for a law firm name that someone had forgotten to insert in the press release's final version?
Someone had forgotten to set up chairs for the audience, and the ventilation system drowned out the doleful efforts of two violinists.
