I could grimace you could grimace she could grimace we could grimace you could grimace they could grimace
V-ing form
I could be grimacing you could be grimacing she could be grimacing we could be grimacing you could be grimacing they could be grimacing
Perfect
I could have grimaced you could have grimaced she could have grimaced we could have grimaced you could have grimaced they could have grimaced
V-ing perfect
I could have been grimacing you could have been grimacing she could have been grimacing we could have been grimacing you could have been grimacing they could have been grimacing
Negation
Simple form
I could not grimace you could not grimace she could not grimace we could not grimace you could not grimace they could not grimace
V-ing form
I could not be grimacing you could not be grimacing she could not be grimacing we could not be grimacing you could not be grimacing they could not be grimacing
Perfect
I could not have grimaced you could not have grimaced she could not have grimaced we could not have grimaced you could not have grimaced they could not have grimaced
V-ing perfect
I could not have been grimacing you could not have been grimacing she could not have been grimacing we could not have been grimacing you could not have been grimacing they could not have been grimacing
Interrogative form
Simple form
could I grimace? could you grimace? could she grimace? could we grimace? could you grimace? could they grimace?
V-ing form
could I be grimacing? could you be grimacing? could she be grimacing? could we be grimacing? could you be grimacing? could they be grimacing?
Perfect
could I have grimaced? could you have grimaced? could she have grimaced? could we have grimaced? could you have grimaced? could they have grimaced?
V-ing perfect
could I have been grimacing? could you have been grimacing? could she have been grimacing? could we have been grimacing? could you have been grimacing? could they have been grimacing?
Interro-negative form
Simple form
could I not grimace? could you not grimace? could she not grimace? could we not grimace? could you not grimace? could they not grimace?
V-ing form
could I not be grimacing? could you not be grimacing? could she not be grimacing? could we not be grimacing? could you not be grimacing? could they not be grimacing?
Perfect
could I not have grimaced? could you not have grimaced? could she not have grimaced? could we not have grimaced? could you not have grimaced? could they not have grimaced?
V-ing perfect
could I not have been grimacing? could you not have been grimacing? could she not have been grimacing? could we not have been grimacing? could you not have been grimacing? could they not have been grimacing?