Formation of the Future Perfect Continuous in the Past
#1. The Future Perfect Continuous in the Past is formed by means of the Future Perfect in the Past of the auxiliary verb to be and Participle I of the notional verb.
#2. In the interrogative form the first auxiliary verb is placed before the subject. And in the negative form the negative particle not is placed after the first auxiliary verb.
| Affirmative | Interrogative | Negative |
|---|---|---|
| I should have been working He would have been working She would have been working We should have been working You would have been working They would have been working |
Should I have been working? Would he have been working? Would she have been working? Should we have been working? Would you have been working? Would they have been working? |
I should not have been working He would not have been working She would not have been working We should not have been working You would not have been working They would not have been working |
#3. The contracted affirmative forms are:
I’d have been working
He’d have been working
The contracted negative forms are:
I shouldn’t have been working
He wouldn’t have been working
#4. The negative-interrogative forms are:
Should I not have been working? = Shouldn’t I have been working?
Would he not have been working? = Wouldn’t he have been working?
Use of the Future Perfect Continuous in the Past
The Future Perfect Continuous in the Past denotes an action lasting during a certain period of time before a definite moment which was future from the point of view of the past.
I wondered how long they would have been packing by the time I returned.