The Perfect Tenses

The Perfect tenses are not interested in the action, but in the completed fact and its relationship to the given general time aspect.
FORM: have + past participle
MEANING: The perfect tenses all give the idea that one thing happens before another time or event.

Present Perfect


I have already eaten.
I finished eating sometime before now. The exact time is not important.

Past Perfect


I had already eaten when they arrived.
First I finished eating. Later they arrived. My eating was completely finished before another time in the past.

Future Perfect

Picture I will already have eaten when they arrive.
First I will finish eating. Later they arrive. My eating will be completely finished before another time in the future.