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