He hasn't come yet.
Tom hasn't met Mary even once.
I think that Tom hasn't left yet.
He hasn't written to them in a long time.
Tom hasn't finished all his homework yet.
Tom hasn't seen Mary for more than a year.
He said he would write to me, but he hasn't.
Tom's already here, but Bill hasn't come yet.
She borrowed the book from him many years ago and hasn't yet returned it.