|Is it seven o’clock already? (The speaker didn’t expect it to be so late.)
|We use already to refer to something which has happened or may have happened before the moment of speaking. Already can sometimes suggest surprise on the part of the speaker, that something is unexpected:
|Is it seven o’clock yet? (The speaker thinks that probably it’s almost seven o’clock.)
|We use yet most commonly in questions and negatives, to talk about things which are expected but which have not happened:
|We use still not yet or already to refer to the continuation of a situation:
|I still meet my friends from my schooldays now and then. (I continue to meet my friends)
|Negatives with yet mean that something has not happened up to now:
|I haven’t spoken to Henry about the car yet.
|Negatives with still suggest that the situation should have changed, but it has not:
|I still haven’t found my passport.
|Negatives with already are far less common than negatives with yet and still. They usually refer to things which should have happened before they did happen:
|If you’ve already registered, the price is 50 pounds. If you haven’t already registered, it’s 75 pounds for late registration.
|now and then
|between now and then
|desde este momento