Already - still - always - yet

ALREADY :

Already is used to say that something has happened earlier than expected or earlier than it might have happened.

"Hurry up Susan. Breakfast is ready!"
"I've already had breakfast thanks. I woke up early."

STILL :

Still is used to refer to continuing situations. "They've been married for 40 years and they still love each other."


ALWAYS :

Always refers to something which happens regularly. "I always send cards at Christmas."


YET :

Yet is used :

- to ask if something expected has happened : "Has the postman arrived yet?"


- to say that something expected hasn't happened : "The postman hasn't arrived yet."

from: Learn English Today