The future perfect tense comes next after the future simple and future continuous.
The future perfect is a verb form or construction used to describe an event that is expected or planned to happen before a time of reference in the future.
In simple words, it refers to an action that will be completed by a certain time in the future.
1. He will have finished his homework by 9 pm.
2. I will have left for work by morning.
3. Hari will not have eaten by now.
The auxiliary verb used in the case of the future perfect tense is "will have". The main verb takes the tense form of "past participle".
Past participle means the verb that typically expresses a completed action. A list of commonly used past participle forms of verbs is given below:
Formation of future perfect tense sentences:
Subject + will have + past participle + rest of the sentence (time reference/adj/adv/noun etc.)
He + will have + finished + his dinner by now.
It + will have + stopped + raining by then.
They + will have + woken + up their whole neighbourhood.
Negative sentence formation :
Subject + will "not" have + past participle + rest of the sentence (time reference/adj/adv/noun etc.)
She + will not have + taught + these portions.
The rain + will not have + stopped + by then.
They + will not have + left + their house.
Will + subject + have (+not) + past participle + rest of the sentence (time reference/adj/adv/noun etc.)
Will + they + have + sung + the carols yet?
Will + she + have not + gone + to school?