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