Future perfect continuous tense

1. Concepts

The future perfect continuous tense is a tense in modern English. Used to describe an action that has been happening up to a point in the future

2. Formula

In there:

- S (subject): Subject

- Will & have: Auxiliary verb

- Been: II participle of "to be" (verb to be)

- V-ing: Verbs add "ing" ending

2.1. Affirmations

S + will + have + been + V-ing

✎ NOTE:

- "been" always comes last "have".

- Passive sentence form of future perfect continuous tense: Will + have + been + being + V3/ed (For example: Nobody has any clue as to who will have been being elected president during the 2034 term of the presidency. => Nobody has any clue who will be elected president in the 2034 presidential term.)

For example:

- By the end of this year, I will have been playing chess for 2 years.

- At the end of this month, she will have been learning yoga for 2 months.

2.2. Negative sentence

S + will + not + have + been + V-ing

✎ NOTE: We just need to add "not" right after the auxiliary verb "will" and we can write "will not" as "won't".

For example:

- I won't have been playing sports for 3 months until the end of this year.
- I won't have been shopping for 3 months until the end of the year. 

2.3. Question sentences

Will + S + have + been + V-ing ?

Reply:

- Yes, S + will

- No, S + won't

✎ NOTE:

Interrogative sentences move the auxiliary verb "will" to the beginning.

Questions using "what, how, when, why,..." have the form: Wh-word + will + S + have + been + V-ing ? (For example: How long will you have been playing chess by the end of the year? => How long will you have played chess by the end of this year?)

For example:

- Will she have been teaching for 5 years by the end of next year?

- Will you have been playing basketball for 2 years by the end of this month? Are you going to have played basketball for 2 years by the end of this month?

3. How to use

3.1. Expresses an action that occurs and continues continuously until a certain time in the future

For example:

I will have been studying English for 10 year by the end of next year.

By August 20th, I will have been working for this company for 20 years.

3.2. Used to emphasize the continuity of an action with another action in the future

For example:

• When I get my degree, I will have been studying at Cambridge for six years. 
• They will have been talking with each other for 4 hour by the time I get home. 

4. Signs of recognition

– by then: until then

– by this December,…: as of December this year

– by the end of this week/month/year: as of this weekend/this month/this year

– by the time+ 1 clause in the present simple tense

5. Some notes when using

➣  The future perfect continuous tense is not used with clauses that begin with words of time such as: when, while, before, after, by the time, as soon as, if, unless... Instead, you can Can use present perfect continuous tense.

For example:

You won’t get a promotion until you will have been working here as long as Tim (false)

=> You won’t get a promotion until you have been working here as long as Nad. (true)

(You won't get promoted until you've worked as long as Nad.)