I could aver you could aver he could aver we could aver you could aver they could aver
V-ing form
I could be averring you could be averring he could be averring we could be averring you could be averring they could be averring
Perfect
I could have averred you could have averred he could have averred we could have averred you could have averred they could have averred
V-ing perfect
I could have been averring you could have been averring he could have been averring we could have been averring you could have been averring they could have been averring
Negation
Simple form
I could not aver you could not aver he could not aver we could not aver you could not aver they could not aver
V-ing form
I could not be averring you could not be averring he could not be averring we could not be averring you could not be averring they could not be averring
Perfect
I could not have averred you could not have averred he could not have averred we could not have averred you could not have averred they could not have averred
V-ing perfect
I could not have been averring you could not have been averring he could not have been averring we could not have been averring you could not have been averring they could not have been averring
Interrogative form
Simple form
could I aver? could you aver? could he aver? could we aver? could you aver? could they aver?
V-ing form
could I be averring? could you be averring? could he be averring? could we be averring? could you be averring? could they be averring?
Perfect
could I have averred? could you have averred? could he have averred? could we have averred? could you have averred? could they have averred?
V-ing perfect
could I have been averring? could you have been averring? could he have been averring? could we have been averring? could you have been averring? could they have been averring?
Interro-negative form
Simple form
could I not aver? could you not aver? could he not aver? could we not aver? could you not aver? could they not aver?
V-ing form
could I not be averring? could you not be averring? could he not be averring? could we not be averring? could you not be averring? could they not be averring?
Perfect
could I not have averred? could you not have averred? could he not have averred? could we not have averred? could you not have averred? could they not have averred?
V-ing perfect
could I not have been averring? could you not have been averring? could he not have been averring? could we not have been averring? could you not have been averring? could they not have been averring?