The future perfect continuous tense expresses actions that will be continued over time that will end in the future. This tense is very rare and almost never necessary to use. It conveys the same meaning as past perfect continuous; the difference is only that it describes the future continued actions.
Formation: To formulate future perfect continuous tense use will have been and present participle of the main verb.
Future Perfect Continuous Tense Formula
Structure: Subject + will + have + been + verb-ing + Object + since/for……
Using since with length of time in the future perfect tense is less common.
- By the end of this year, she will have been teaching in this school for five years.
- The son will not have been studying for three hours by the time his father comes home.
- She will have been writing assignments for one hour by the time we reach her place.
- His wife will have been cleaning the home for thirty minutes.
- The girl will have been carrying your bag for ten minutes before you arrive.
- We hope that the other students will have been preparing their projects when we get to school today.
- His little daughter will have been sitting quietly for three hours when the game finishes.
Inserting the word, not after the auxiliary will, will make the tense negative. The negative of the future perfect continuous tense is not very common.
Structure: Subject + will + not + have + been + verb-ing + Object + since/for……
- We will not have been working for two days.
- I will not have been smoking before my dinner is ready.
- I will not have been walking for one hour to the garden before they come.
- The baby will not have been sleeping for very long, but I have to wake him up.
- The police will not have been investigating you for three days before they know everything about you.
- I will not have been presenting our project for one hour to the class when my friends join me.
Structure: Will + Subject + have + been + verb-ing + Object + since/for……
- How long will you have been working on this project when you finally complete it?
- How long will you have been teaching English when you shift to this city?
- Will the girl have been walking along the road that leads to the garden for several minutes when she sees her brother there?
- Will I have been paying the rent for two years before I leave the house?
- Whose friend will have been searching for several days before finding a good product?
- By what time will the pandemic have been spreading to the rest of the world for many years?
Uses of the Future Perfect Continuous Tense
1. We used it to show an action that will happen over time before something in the future. The same idea can be expressed by future perfect tense as well if we add the length of time to it. But sometimes, only one of these two tenses would sound correct.
He will have been working on this assignment when he goes to school today at 9:00.
(It shows that the action ‘work on this assignment will happen overtime before the action ‘go to school.’)
2. It is also describes a repeated action that we expect to have been happening in the past and up to the present time.
It is time to discuss the topic many of the students will have been discussing themselves.
The future perfect continuous isn’t used very much. Other tenses can be used instead of it. Therefore, it is a bit harder to find a good example of future perfect continuous tense.
Like other continuous tenses, non-action or stative verbs cannot be used in the future perfect continuous tense.