AFFIRMATIVE SENTENCES

In this tense with — shall or will + have been + first form of verb & ing is used. For showing time — Since or for is used.

Since is used for a point of time & For is used for duration of time i.e. Since morning, For two hours.

For Example:

• We shall have been living here for the last two years.
• The boys will have been making a noise since 1 p.m.
• You have been doing your job for three years.

NEGATIVE SENTENCES

In these sentences with ‘shall or will + have + not + been + first form of verb & ing is used. For showing time — Since or For is used.

For Example:

• I shall not have been reading my book for two hours.
• You will not have been singing since morning.
• They will not have been doing their work since morning.

INTERROGATIVE SENTENCES

In these sentences— shall or will is used before subject.
And – have + not + been + first form of verb & ing is used.
To express time ‘Since’ or ‘for’ is used.

For Example:

• Shall we have been playing a match since morning?
• Will you have been taking this medicine for a week?
• Will he have been staying with you for a year?

Similarly in interrogative negative sentences ‘shall or will’ is used before subject and not & have been is used before first form of verb and ‘ing’ in the sentence.
To express time ‘For’ or ‘Since’ is used.

For Example :

• Shall we not have been entertaining the guests since morning?
• Will you not have been flying kites since morning ?
• Will the birds not have been flying in the sky for two hours?