I can chap you can chap she can chap we can chap you can chap they can chap
V-ing form
I can be chapping you can be chapping she can be chapping we can be chapping you can be chapping they can be chapping
Perfect
I can have chapped you can have chapped she can have chapped we can have chapped you can have chapped they can have chapped
V-ing perfect
I can have been chapping you can have been chapping she can have been chapping we can have been chapping you can have been chapping they can have been chapping
Negation
Simple form
I cannot chap you cannot chap she cannot chap we cannot chap you cannot chap they cannot chap
V-ing form
I cannot be chapping you cannot be chapping she cannot be chapping we cannot be chapping you cannot be chapping they cannot be chapping
Perfect
I cannot have chapped you cannot have chapped she cannot have chapped we cannot have chapped you cannot have chapped they cannot have chapped
V-ing perfect
I cannot have been chapping you cannot have been chapping she cannot have been chapping we cannot have been chapping you cannot have been chapping they cannot have been chapping
Interrogative form
Simple form
can I chap? can you chap? can she chap? can we chap? can you chap? can they chap?
V-ing form
can I be chapping? can you be chapping? can she be chapping? can we be chapping? can you be chapping? can they be chapping?
Perfect
can I have chapped? can you have chapped? can she have chapped? can we have chapped? can you have chapped? can they have chapped?
V-ing perfect
can I have been chapping? can you have been chapping? can she have been chapping? can we have been chapping? can you have been chapping? can they have been chapping?
Interro-negative form
Simple form
can I not chap? can you not chap? can she not chap? can we not chap? can you not chap? can they not chap?
V-ing form
can I not be chapping? can you not be chapping? can she not be chapping? can we not be chapping? can you not be chapping? can they not be chapping?
Perfect
can I not have chapped? can you not have chapped? can she not have chapped? can we not have chapped? can you not have chapped? can they not have chapped?
V-ing perfect
can I not have been chapping? can you not have been chapping? can she not have been chapping? can we not have been chapping? can you not have been chapping? can they not have been chapping?