Perfect Tenses

Present Perfect = HAVE/HAS + Past Participle Verb

1. An action that already happened before NOW but don't know when it happened.
For Ex: I have already watched that movie. (Time? Do not know)

2. An action that has been repeated a few times before NOW but Don't Know when exactly.
For Ex: I have read that book 5 times!! (Did this action 5 times, when? Not known)

3. Use with Since and For means until NOW still true:
For Ex: We have studied in MMU for 11 weeks (Still here)

Present Perfect Progressive = HAVE/HAS BEEN+ VERB+ING

An action that is still happening UNTIL NOW and you want to show HOW LONG (FOR) or SINCE WHEN (SINCE):

Ex: I have been waiting for her for 1 hour ~means you are still waiting for her.


Past Perfect~ HAD+ PAST PARTICIPLE VERB

1. to show Past Past ^^ to show an action/ situation in the past already happened but before that action, another action actually had happened much earlier.

For Ex: It was midnight and she asked me to join her for supper. I didn't accept her invitation because I had taken a late dinner. (means dinner was taken before she asked you)