I’ve just … I’ve already …I haven’t … yet (present perfect 2)

Question 1

just =

Answer 1

a short time ago
A: Are Laura and Paul here?
B: Yes, they’ve just arrived

Question 2

already =

Answer 2

before you expected / before I expected
A: What time are Laura and Paul coming?
B: They’ve already arrived.(= before you expected)

Question 3

yet =

Answer 3

until now
We use yet in negative sentences and questions.
Yet is usually at the end.

Yet in negative sentences (I haven’t … yet)
A: Are Laura and Paul here?
B: No, they haven’t arrived yet.(but B expects Laura and Paul to arrive soon)

Yet in questions (Have you … yet?)
A: Have Laura and Paul arrived yet?
B: No, not yet. We’re still waiting for them