Future Perfect in the Past образуется так же, как и Future Perfect, с той лишь разницей, что вместо shall и will употребляются соответственно should и would:
| Утвердительная форма | Отрицательная форма |
| I should have worked | I should not have worked |
| Не (she, it) would have worked | He (she, it) would not have worked |
| We should have worked | We should not have worked |
| You would have worked | You would not have worked |
| They would have worked | They would not have worked |
В разговорной речи употребляются те же сокращения, что и в Future Indefinite in the Past:
| I'd have worked |
| he'd have worked |
| I shouldn't have worked |
| I'd not have worked |
| he wouldn't have worked |
| he'd not have worked |
и т.д.
Future Perfect in the Past заменяет Future Perfect в придаточных предложениях, когда сказуемое главного предложения выражено глаголом в прошедшем времени.
Future Perfect in the Past, как и Future Perfect, переводится на русский язык будущим временем глагола совершенного вида:
| I said that I should have copied the text by five o'clock. | Я сказал, что я (уже) перепишу текст к пяти часам. |
| Не said that he would, have taken his examinations by the first of July. | Он сказал, что он (уже) сдаст экзамены к первому июля. |