We use yet as an adverb to refer to a time which starts in the past and continues up to the present. We use it mostly in negative statements or questions in the present perfect. It usually comes in end position:
Kevin hasn’t registered for class yet.
I haven’t finished my breakfast yet.
Has she emailed you yet?
We don’t use yet to refer to something that has happened. We use already:
She’s booked the flights already.
Not: She’s booked the flights yet.
We don’t use yet to talk about events that are continuing:
Elizabeth is still living in Manchester. She’s not moving to London till next month.
Not: Elizabeth is living yet … or Elizabeth is yet living …
Yet with negative statements
When we use yet in negative statements, it shows that an event is expected to happen in the future:
Jason hasn’t phoned yet. (I am expecting him to phone.)
I haven’t seen ‘Who Framed Roger Rabbit’ yet. (I am expecting to see this film.)
Yet with questions
When we use yet in an affirmative question, it shows that the speaker is expecting something to happen:
Is he home yet? (I expect that he will be home at some point.)
Has your passport arrived yet? (I expect that your passport will arrive in the post.)
Negative questions with yet can express an even stronger expectation that something will happen. When we ask this type of question, we expect a negative answer:
Hasn’t Richard arrived yet? (I strongly expect that he should have arrived.)
Haven’t you done your driving test yet? (I feel you should have done your driving test by now.)
Yet with affirmative statements
When we use yet in affirmative statements, it shows that a situation is continuing, even when we might expect it not to continue:
There’s plenty of time yet. (even though you don’t think so)
We’ve got a lot more work to do yet. (even though you think we have finished)
Yet with superlatives
We often use yet after superlatives:
His latest film is his best yet. (The film is the best one he has made up to now.)
Two hours and 15 minutes – that’s Jones’s fastest marathon yet!
Yet as a conjunction
Yet as a conjunction means ‘but’ or ‘nevertheless’. We use it to show contrast. It often occurs after and:
So many questions and yet so few answers.
It felt strange and yet so wonderful to ski in the summer!
Yet for emphasis
We use yet for emphasis, with a meaning similar to ‘even’, especially before more, another and again:
The cook arrived with yet another plate of cake.
The printer’s broken down yet again! (It has broken down many times before.)
As yet means ‘up to now, but the situation will definitely change’. We only use it in negative contexts:
The film shows you the most typical places, as yet untouched by tourism, and how to get there.
Have yet to and be yet to
We use have yet to and be yet to in more formal contexts. We use them to refer to events which are necessary or which must happen at some time, but which have not happened at the time of speaking:
The price of the tickets for the concert has yet to be decided. (The price will be decided.)
The President and her husband are yet to arrive. (The President and her husband will arrive.)