As we have seen in the previous lessons on the future tenses, there are two ways to express the future in English. In contrast to the future simple, in the future perfect simple the use of the two different forms is generally interchangeable.
Subject + “will have” + past participle…
Subject + auxiliary verb (to be) + “going to have” + past participle…
| ||The party will [is going to] have ended by the time you finish work.|
| ||I’ll [I’m going to] have eaten before we meet.|
Subject + “will” + “not” + “have” + past participle…
Subject + auxiliary verb (to be) + “not” + “going to have” + past participle…
| ||The party won’t [isn’t going to] have ended by the time you finish work.|
| ||I won’t [I’m not going to] have eaten before we meet.|
3. Interrogative Sentences
“Will” + subject + “have” + past participle…?
Auxiliary verb (to be) + subject + “going to have” + past participle…?
| ||Will [Is] the party [going to] have ended before you finish work?|
| ||Will [Are] you [going to] have eaten before we meet?|
1. We use the future perfect for actions that will have finished before another action in the future. The future perfect can also be used to express something that will happen before a specific time in the future.
| ||I’ll have finished my studies before I start my new job.|
| ||Is Mike going to have trained enough before his first game?|
| ||We won’t have become fluent in Spanish by the time we leave for Mexico next month.|
2. The future perfect is use to show that something is going to continue until another action or event in the future.
| ||Karen is going to have worked for 50 years by the time she retires.|
| ||Next week, I’ll have lived in Germany for 1 year.|