"Yet" loosely indicates that something will happen. (Future) "I haven't done that thing that I'm supposed to do in the future yet." "Already" loosely indicates that something happened. (Past) "I already did that thing in the past." Here's some examples where only the one would work: "I'm not there yet" ("I have yet to arrive") "Have you submitted the assignment yet?" ("Not yet) "I submitted the assignment already" "I'm here already" I hope this helps.

When using "yet" you are saying that it must still happen or it hasn't happened . eg. "She hasn't received her book yet" or "She is yet to receive her book" "Already"- it has happened. eg. "I cannot have dinner with you tonight as I have already made plans for tonight" Hope it helps!