Perfect

Perfect is the name given to those forms of the verb constructed with have and the past participle (third form) of the verb. These forms are often known as tenses, though many modern writers prefer to consider them as aspects; The four perfect aspect forms are as follows:

1. The Present Perfect: I have worked here for over twenty years. - You have gone

2. The Present Perfect Progressive (or Present Perfect Continuous): He has been working. - They have been living.

3. The Past Perfect: We had worked it all out. - I had spoken to him on several occasions.

4. The Past Perfect Progressive (or Past Perfect Continuous): I had been working all morning on that. - He had been living there until he got that new place.

Some writers call #1 the Present Perfect Simple and #3 the Past Perfect Simple, but most prefer to use the word 'Simple' only for tenses that are both non-progressive and non-perfect, i.e. the Present Simple and Past Simple.

The perfect tenses in English are used to relate two time points or periods: 1. the time at which the situation denoted occurred or began, and 2. a later time point or period. It has been suggested that 'Retrospective' would be a more appropriate name for these forms.