Here are examples of sentences in the future perfect continuous tense:
1. Positive Sentences
I will have been studying for three hours by the time the exam starts.
She will have been working at the company for five years by next month.
They will have been playing football for two hours when it starts to rain.
We will have been traveling for 24 hours by the time we reach our destination.
He will have been living in that house for a decade by next year.
2. Negative Sentences
I will not (won’t) have been working on the project for long by the time it’s due.
She will not (won’t) have been exercising regularly before the competition.
They will not (won’t) have been studying enough to pass the exam.
We will not (won’t) have been waiting here for two hours when they finally arrive.
He will not (won’t) have been practicing the piano before the recital.
3. Questions
Will you have been working on the report for a week by the deadline?
Will she have been studying for the exam for a month by then?
Will they have been living in the city for a year by the end of this month?
Will he have been driving for over six hours when he arrives?
Will we have been waiting for long when the meeting starts?
4. Uses
To indicate the duration of an activity that will continue up to a specific point in the future: By 5 PM, I will have been working here for ten hours.
To emphasize the length of time spent on an activity before a future event: They will have been playing for hours when the match ends.