Future Perfect - English

English

In English, the tense is formed thus:

This is sometimes shortened with the contraction of 'll for shall or will: I'll have been hit, you'll have been paid, etc. To make this form negative, one simply adds not between will or shall and have. For the contracted form, will not becomes won't and shall not becomes shan't: I won't have been speaking, you shan't have been speaking, etc.

The English future perfect places the action relative only to the absolute future reference point but provides no information on location in time relative to the present : for example, If it rains tomorrow, we will have worked in vain yesterday.

The time of perspective of the English future perfect can be shifted from the present to the past by replacing will with its past tense form would, thus effectively creating a "past of the future of the past" construction in which the indicated event or situation occurs before a time that occurs after the past time of perspective (but the event or situation must occur after the time of perspective): In 1982, I knew that by 1986 I would have already gone to prison.

Unlike the English present perfect, the future perfect permits the use of a specific time marker for the action: I will have done it on the previous Tuesday is correct, while the present perfect formulation I have done it last Tuesday is incorrect.

An obsolete term found in old grammars for the English future perfect is the "second future tense."