Already is used to show that something has happened earlier. It is used in the mid-position of the sentence and is usually used with Present Perfect.
In American English, it is also possible to use already with the Simple Past.
Already in a sentence:
- I have already done my homework.
- He has already washed the car.
- I already did my homework.
- He already washed the car.
Still is used to show a continuous action, and is used in affirmative sentences.
Still is used in the mid-position of the sentence. And is usually used with Present Continuous (Progressive).
Still in a sentence:
- I am still doing my homework.
- He is still washing his car.
Still requires the use of Progressive forms. Except for the verbs be, have and verbs of primary perception*. Or when you want to indicate a habitual situation (HABIT).
- I still have the book that you gave me.
- I am still a strong guy.
- I can still hear< him.
- I still see her outside.
- She still <goes jogging in the park. – HABIT
- He still shops at TARGET. – HABIT
NOTE: still is rarely used in negative sentences. It is usually replaced by ‘not…anymore’ or ‘no longer’
- I no longer< have the book that you gave me.
- I am not a strong guy anymore.
* Verbs of primary perception: see, hear, taste, smell, listen, feel, watch.
Yet is used to talk about something that is expected to happen, but did not happen till this moment.
Yet means at any time up to now.
Yet is used in interrogative (questions) and negative sentences.
Yet is usually used with Present Perfect. Yet is used in the end of the sentence.
Yet in a sentence:
- Have you finished your homework yet? – Interrogative
- I haven’t washed my car yet. – Negative
Yet is very rarely used in affirmative sentences, but when it is used, it implies a negative.
- I have yet to read the ‘Harry Potter and the Goblet of Fire’ book
= I have not read the ‘Harry Potter and the Goblet of Fire’ book yet, but I will probably read it soon.
Just is used when we want to say that something happened a short time ago (very recently).
It is always used with Present Perfect or Past Perfect.
It is used between the auxiliary verb (have/has) and past participle.
Just can be used in affirmative and interrogative sentences.
Just in a sentence:
- I’ve just called my grandmother. (Present Perfect)
- Have you just called your grandmother? (Present Perfect)
- We had just< finished dinner. (Past Perfect)
NOTE: In American English just can be used with Simple Past.
- I just saw him outside.
- I just called my grandmother.