STILL, YET, and ALREADY are adverbs of time that tell us WHEN something happened or will happen (or not). They can be confusing, so I’m going to explain how to use them.
Still is used to express that a situation that began in the past continues until now without change. It is placed in the middel of a sentence and can be used in affirmative, negative and interrogative sentences.
YET is used to refer to something that did not happen before now, but is expected to happen. It is placed at the end of the sentence (or clause) and is used in negative and interrogative sentences.
STILL and YET can both be used in negative sentences to express that something hasn’t happened before now, They are similar but STILL shows a higher level of impatience. Also remember that YET goes at the end of the sentence.
ALREADY is used to express that something happened sooner than expected.