Pefect aspect

The perfect aspect is a grammatical aspect that refers to a state resulting from a previous action (also described as a previous action with relevance to a particular time, or a previous action viewed from the perspective of a later time).

The perfect aspect is not the same as the perfective aspect. See the perfective vs. perfect section of Grammatical aspect.

For example, "I have eaten lunch" implies both that a previous action happened ("I ate lunch") and that a current state resulted ("I am full"). This differs from the simple "I ate lunch", which implies only that an action happened, with no relevance to the present. The form "I have eaten" is referred to as a present perfect, meaning present tense, perfect aspect. (It is considered present tense instead of a past tense because the resulting state is in the present.)

In English, the perfect aspect can be combined with any simple tense (past, present or future), yielding perfect tenses that are formed using the conjugations of the auxiliary verb have and a verb:


 * Present perfect: I have thrown the ball, passive The ball has been thrown by me.
 * Past perfect (pluperfect): I had thrown the ball, passive The ball had been thrown by me.
 * Future perfect: I will (or shall) have thrown the ball, passive The ball will have been thrown by me.

In addition to these, we can distinguish the three perfect progressive tenses:


 * Present perfect progressive: I have been throwing the ball, passive The ball has been being thrown by me.


 * Past perfect progressive: I had been throwing the ball, passive The ball had been being thrown by me.


 * Future perfect progressive: I will (or shall) have been throwing the ball, passive The ball will have been being thrown by me.

The perfect aspect can also be combined with various modal auxiliary verbs, such as would, should, could, may or might:


 * Conditional perfect: I would have thrown the ball, passive The ball would have been thrown by me.
 * should-perfect: I should have thrown the ball, passive The ball should have been thrown by me.

Progressives can likewise be formed from these:


 * Conditional perfect progressive: I would have been throwing the ball, passive The ball would have been being thrown by me.
 * should-perfect progressive: I should have been throwing the ball, passive The ball should have been being thrown by me.

While simple combinations (like the present perfect) are common in spoken and written English, more complex combinations (like the passive future perfect progressive) are rarely encountered.

The various perfect progressive passives are a fairly recent addition to English, and some speakers still find them questionable or even ungrammatical.