Future Perfect Continuous Tense

Future perfect continuous tense describes an action that will continue over a period of time in the future. In this tense, after 'shall/will', 'have been' is used, followed by the fourth form (V4), the continuous form of the verb. The structure of the sentence is:

Subject + shall/will + have been + V4 (ing form of verb) + other words

Examples:

I shall have been dancing.
We shall have been playing.
You will have been reading for six hours.
They will have been teaching in this school for twenty years.
He /she will have been living here for four years.
By the end of this year, I will have been completing my work.
By 12^th March we will have been painting this wall for the next two months.

Future perfect continuous tense in all kinds of sentences

1. Affirmative sentence: In the affirmative sentence of future perfect continuous tense, 'have been' is used, followed by the fourth form (V4) of the verb. The structure of the sentence is;

Subject + shall/will + have been + V4 + other words

Examples:

I shall have been baking the cake.
We shall have been baking the cake.
You will have been baking the cake.
He/she will have been baking the cake.
They will have been baking the cake.
John will have been baking the cake.
Girls will have been baking the cake.
I will have been completing my project until next week of this month.
By this month, we will have been preparing for our coming examination.

2. Negative sentence: In the negative sentence of future perfect continuous tense, 'not' is used before 'have been'. The structure of the sentence is:

Subject + shall/will + not + have been + V4 + other words.

Examples:

I shall not have been baking the cake.
We shall not have been baking the cake.
You will not have been baking the cake.
He/she will not have been baking the cake.
They will not have been baking the cake.
John will not have been baking the cake.
Girls will not have been baking the cake.
I will not have been completing my project until the next week of this month.
We will not have been preparing for our coming examination by this month.

3. Interrogative sentence: In the interrogative sentence of future perfect continuous tense, 'shall/will' is used before the subject, and 'have been' is used after the subject. The structure of the sentence is:

Shall/will + subject + have been + V4 + other words

Examples:

Shall I have been baking the cake?
Shall we have been baking the cake?
Will you have been baking the cake?
Will he/she have been baking the cake?
Will they have been baking the cake?
Will john have been baking the cake?
Will girls have been baking the cake?
Shall I have been completing my project until next week of this month?
By this month, shall we have been preparing for our coming examination?

4. Negative interrogative sentence: In the negative interrogative sentence of future perfect continuous tense, 'not' is used between the subjects and 'have been'. The structure of the sentence is:

Shall/will + subject + not + have been + V4 + other words

Examples:

Shall I not have been baking the cake?
Shall we not have been baking the cake?
Will you not have been baking the cake?
Will he/she not have been baking the cake?
Will they not have been baking the cake?
Will john not have been baking the cake?
Will girls not have been baking the cake?
Shall I not have been completing my project until next week of this month?
By this month, shall we not have been preparing for our coming examination?

Uses of future perfect continuous tense

It is used to describe an action that will continue over a certain period of time in the future. This tense tells about that action which is in progress for a long time in the future.

Example: By next year, he will have been preparing for the IAS examination for two years. Raj will have been working in his new company for five years.