More Examples:

• She will have been working on this project for three months by the time she finishes.
• They will have been traveling for a week by the time they reach their destination.
• We will have been discussing about the issue by 4 o’clock in the afternoon.
• By the time my sister comes, I will have been reading my favorite book for over an hour.
• We will not have been living in this city for five years by the time we celebrate our anniversary.
• The children will have been playing for three hours by the time the bell rings.
• By the time the deadline is due, we will not have been accepting applications.
• I will have been studying for two hours by the time my exam starts.
• Mrs. Jones will have been teaching English for thirty years by the end of this year.
• He will not have been donating to the orphanage for a month by next week.

Additional Notes:

• The future perfect continuous is often used with expressions of time, such as “by then,” “by the time,” “until,” and “when.”
• The future perfect continuous can also be used in conditional sentences to express future actions that are dependent on certain conditions.
• This is not an easy perfect tense in English as it is also seldom used in conversations.
• The function expressing mental or physical state can cause confusion to learners.
• The future continuous is more likely to be used than future perfect continuous in informal language.

Conclusion

It is essential that language learners study deeper and be familiar with the functions of the future perfect continuous because it can help them improve their grammar skills. In professional contexts, the future perfect continuous is used where advanced English language learners apply it in their conversations, or even in their writing.

The future perfect continuous may not be easy to use, but you just need more practice to perfect it. Never stop learning it – always seek for improvement of your grammar skills. Who knows, by the time you age 50, you will have been applying it in your conversations.

Check Your Understanding

Answer the following exercise by filling in the blanks with the correct form of the future perfect continuous.

1. Mary and John _____________ (watch TV) for thirty minutes by the time their order is delivered.
2. Jones _____________ (work) in his company for thirty years before he retires this December.
3. By this time next month, we ______________ (live) in this city for ten years.
4. My mom needs to take a rest as she ________________ (clean) the house the entire day.
5. Her cousin ______________ (stay – negative) in her dormitory for over a week by today.
6. The baby _______________ (sleep) for twelve hours by the time she wakes up.
7. She _____________ (work – negative) on this project for three weeks by the time the deadline comes.
8. By the time we reach our destination this afternoon, we ______________ (drive) for five hours.
9. By the end of the year, I ________________ (study – negative) Spanish for two years.
10. By the time the movie starts, we ______________ (wait) in line for an hour.
11. The company _______________ (operate) for twenty years by the time they celebrate their anniversary.
12. The construction workers ______________ (build) the new bridge for a year by the time it is completed.
13. The family _______________ (live – negative) in their new house for five years by the time their child graduates from high school.
14. The students _____________ (study) for their exams for two weeks by the time the test day arrives.
15. The athletes ______________ (train) for months by the time the competition begins.

Check your answers here.