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