These words are often used with the present perfect tense although yet, still and already can all be used with other tenses.
‘Just’ is usually used only with the present perfect tense and it means ‘a short time ago’.
I’ve just seen Susan coming out of the cinema.
Mike’s just called. Can you ring him back please?
Have you just taken my pen? Where has it gone?
In the present perfect, ‘just’ comes between the auxiliary verb (‘have’) and the past participle.
‘Yet’ is used to talk about something which is expected to happen. It means ‘at any time up to now’. It is used in questions and negatives.
Have you finished your homework yet? The speaker expects that the homework will be finished.
I haven’t finished it yet. I’ll do it after dinner.
‘Yet’ usually comes at the end of the sentence.
‘Still’ is used to talk about something that hasn’t finished – especially when we expected it to finish earlier.
I’ve been waiting for over an hour and the bus still hasn’t come.
You promised to give me that report yesterday and you still haven’t finished it.
‘Still’ usually comes in ‘mid-position’, but with present perfect, it comes before the auxiliar 'have'
Still is often used with other tenses as well as the present perfect.
Present simple: I’ve still got all those letters you sent me.
Present continuous: Are you still working in the bookshop?
‘Already’ is used to say that something has happened early – or earlier than it might have happened.
I’ve already spent my salary and it’s two weeks before pay day.
The train’s already left! What are we going to do?
‘Already’ usually comes in mid-position.