I. The formation of thePerfect Continuous Tense

The Future Perfect is formed by means of the Future Indefinite of the auxiliary verb to have and Participle II of the notional verb.

In the interrogative form the auxiliary verb is placed before the subject.

In the negative form the negative particle not is placed after the first auxiliary verb.

II. The contracted affirmative forms are:

I’ll have worked

We’ll have worked

The contracted negative forms are:

I shan’t have worked

He won’t have worked

The negative-interrogative forms are:

Will he not have worked?

Won’t he have worked?

Shall we not have worked?

Shan’t we have worked?

III. The use of the Future Perfect

The Future Perfect denotes an action completed before a definite moment in the future d viewed back from that future moment.

By six o’clock I shall have finished my translation.

(That means that the action of finishing will take place before six o’clock.)

I shall be back by six, and I hope you will have had a good sleep by that time.

Like the Past Perfect, the Future Perfect may be purely temporal and may show that the action already accomplished at the given future moment is connected in its results or consequences with that future moment.

Tomorrow at three o’clock he will have received my letter.

(He will have the letter).

When you have finished this book, you will have learnt many new words and

expressions.

(You will know those words and expressions).

◆ The future moment from which the completed action is viewed may be indicated:

a) by means of an adverbial expression: by that time, by the first of June, by seven o’clock, etc.:

By the end of the term we shall have learnt many new words and expressions.

By this time tomorrow they will have crossed the Channel.

b) By means of another action:

If you come at seven, I shall have done my work.

If you ring me up after seven o’clock, I shall have spoken to the secretary.

The Future Perfect can denote an action which will begin before a definite moment in the future, will continue up to that moment and will be going on at that moment. This meaning is shown by the context.

By the first of July we shall have been at the seaside for a fortnight.

We shall have known each other for five years by the end of this year.

Future perfectis used with verbs not admitting of the Continuous form, in negative sentences, with non-terminative verbs such as to work, to live, to study, to teach etc.

I shall have been a teacher for 20 years by next May.

I shall have worked as a teacher for 20 years by next May.