I can unscrew you can unscrew he can unscrew we can unscrew you can unscrew they can unscrew
V-ing form
I can be unscrewing you can be unscrewing he can be unscrewing we can be unscrewing you can be unscrewing they can be unscrewing
Perfect
I can have unscrewed you can have unscrewed he can have unscrewed we can have unscrewed you can have unscrewed they can have unscrewed
V-ing perfect
I can have been unscrewing you can have been unscrewing he can have been unscrewing we can have been unscrewing you can have been unscrewing they can have been unscrewing
Negation
Simple form
I cannot unscrew you cannot unscrew he cannot unscrew we cannot unscrew you cannot unscrew they cannot unscrew
V-ing form
I cannot be unscrewing you cannot be unscrewing he cannot be unscrewing we cannot be unscrewing you cannot be unscrewing they cannot be unscrewing
Perfect
I cannot have unscrewed you cannot have unscrewed he cannot have unscrewed we cannot have unscrewed you cannot have unscrewed they cannot have unscrewed
V-ing perfect
I cannot have been unscrewing you cannot have been unscrewing he cannot have been unscrewing we cannot have been unscrewing you cannot have been unscrewing they cannot have been unscrewing
Interrogative form
Simple form
can I unscrew? can you unscrew? can he unscrew? can we unscrew? can you unscrew? can they unscrew?
V-ing form
can I be unscrewing? can you be unscrewing? can he be unscrewing? can we be unscrewing? can you be unscrewing? can they be unscrewing?
Perfect
can I have unscrewed? can you have unscrewed? can he have unscrewed? can we have unscrewed? can you have unscrewed? can they have unscrewed?
V-ing perfect
can I have been unscrewing? can you have been unscrewing? can he have been unscrewing? can we have been unscrewing? can you have been unscrewing? can they have been unscrewing?
Interro-negative form
Simple form
can I not unscrew? can you not unscrew? can he not unscrew? can we not unscrew? can you not unscrew? can they not unscrew?
V-ing form
can I not be unscrewing? can you not be unscrewing? can he not be unscrewing? can we not be unscrewing? can you not be unscrewing? can they not be unscrewing?
Perfect
can I not have unscrewed? can you not have unscrewed? can he not have unscrewed? can we not have unscrewed? can you not have unscrewed? can they not have unscrewed?
V-ing perfect
can I not have been unscrewing? can you not have been unscrewing? can he not have been unscrewing? can we not have been unscrewing? can you not have been unscrewing? can they not have been unscrewing?