I could chap you could chap he could chap we could chap you could chap they could chap
V-ing form
I could be chapping you could be chapping he could be chapping we could be chapping you could be chapping they could be chapping
Perfect
I could have chapped you could have chapped he could have chapped we could have chapped you could have chapped they could have chapped
V-ing perfect
I could have been chapping you could have been chapping he could have been chapping we could have been chapping you could have been chapping they could have been chapping
Negation
Simple form
I couldn't chap you couldn't chap he couldn't chap we couldn't chap you couldn't chap they couldn't chap
V-ing form
I couldn't be chapping you couldn't be chapping he couldn't be chapping we couldn't be chapping you couldn't be chapping they couldn't be chapping
Perfect
I couldn't have chapped you couldn't have chapped he couldn't have chapped we couldn't have chapped you couldn't have chapped they couldn't have chapped
V-ing perfect
I couldn't have been chapping you couldn't have been chapping he couldn't have been chapping we couldn't have been chapping you couldn't have been chapping they couldn't have been chapping
Interrogative form
Simple form
could I chap? could you chap? could he chap? could we chap? could you chap? could they chap?
V-ing form
could I be chapping? could you be chapping? could he be chapping? could we be chapping? could you be chapping? could they be chapping?
Perfect
could I have chapped? could you have chapped? could he have chapped? could we have chapped? could you have chapped? could they have chapped?
V-ing perfect
could I have been chapping? could you have been chapping? could he have been chapping? could we have been chapping? could you have been chapping? could they have been chapping?
Interro-negative form
Simple form
couldn't I chap? couldn't you chap? couldn't he chap? couldn't we chap? couldn't you chap? couldn't they chap?
V-ing form
couldn't I be chapping? couldn't you be chapping? couldn't he be chapping? couldn't we be chapping? couldn't you be chapping? couldn't they be chapping?
Perfect
couldn't I have chapped? couldn't you have chapped? couldn't he have chapped? couldn't we have chapped? couldn't you have chapped? couldn't they have chapped?
V-ing perfect
couldn't I have been chapping? couldn't you have been chapping? couldn't he have been chapping? couldn't we have been chapping? couldn't you have been chapping? couldn't they have been chapping?