English verb conjugation
COULD WHIRR

Regular verb: whirr - whirred - whirred

Affirmation

Simple form	V-ing form
I could whirr you could whirr he could whirr we could whirr you could whirr they could whirr	I could be whirring you could be whirring he could be whirring we could be whirring you could be whirring they could be whirring
Perfect	V-ing perfect
I could have whirred you could have whirred he could have whirred we could have whirred you could have whirred they could have whirred	I could have been whirring you could have been whirring he could have been whirring we could have been whirring you could have been whirring they could have been whirring

Negation

Simple form	V-ing form
I could not whirr you could not whirr he could not whirr we could not whirr you could not whirr they could not whirr	I could not be whirring you could not be whirring he could not be whirring we could not be whirring you could not be whirring they could not be whirring
Perfect	V-ing perfect
I could not have whirred you could not have whirred he could not have whirred we could not have whirred you could not have whirred they could not have whirred	I could not have been whirring you could not have been whirring he could not have been whirring we could not have been whirring you could not have been whirring they could not have been whirring

Interrogative form

Simple form	V-ing form
could I whirr? could you whirr? could he whirr? could we whirr? could you whirr? could they whirr?	could I be whirring? could you be whirring? could he be whirring? could we be whirring? could you be whirring? could they be whirring?
Perfect	V-ing perfect
could I have whirred? could you have whirred? could he have whirred? could we have whirred? could you have whirred? could they have whirred?	could I have been whirring? could you have been whirring? could he have been whirring? could we have been whirring? could you have been whirring? could they have been whirring?

Interro-negative form

Simple form	V-ing form
could I not whirr? could you not whirr? could he not whirr? could we not whirr? could you not whirr? could they not whirr?	could I not be whirring? could you not be whirring? could he not be whirring? could we not be whirring? could you not be whirring? could they not be whirring?
Perfect	V-ing perfect
could I not have whirred? could you not have whirred? could he not have whirred? could we not have whirred? could you not have whirred? could they not have whirred?	could I not have been whirring? could you not have been whirring? could he not have been whirring? could we not have been whirring? could you not have been whirring? could they not have been whirring?