Future perfect tense
Usage
Time frame: The future perfect tense is used to talk about actions that will have been completed at a specific time in the future.
By the time you arrive, we will have finished dinner.
Anticipation: The future perfect tense is often used to describe an action that is expected to be completed in the future:
I will have completed my project by the deadline.
Cause and effect: The future perfect tense can be used to describe a cause-and-effect relationship between two future events. The earlier event is described using the future perfect tense, while the later event is described using the simple future tense.
I will have finished my homework, so I can go to the party.
Form
The future perfect tense is formed using the auxiliary verb will have followed by the past participle (-ed form) of the main verb.
Signal words
Signal words such as by, by the time, by then, by the year, by the end of, by the deadline, etc. are often used with the future perfect tense to give context and indicate the time frame of the action.
Negation and question forms
To form negative sentences in the future perfect tense, the word not is placed between will and have:
I will not have finished my work by then.
To form questions in the future perfect tense, the auxiliary verb will is moved before the subject:
Will you have finished your work by then?