Past continuous (i was working)

Present perfect (I have worked)

present perfect continuous (I have been working)

Past continuous is used when you did something in the past but this action is still continuing.

Example: I was walking;

Presente perfect is used when you did something in the past, but there is not a specific time.

Example: I have read a book (I don't use a specific time here)

Present perfect continuous is used when you did something in the past (there is not a specific time as well) and this action affects the current time.

Example: I have been waiting for a while.

Present perfect continuous (i have been walking)

Present perfect (I have walked)

Past perfect(I was walking)