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 could not lap you could not lap he could not lap we could not lap you could not lap they could not lap
V-ing form
I could not be lapping you could not be lapping he could not be lapping we could not be lapping you could not be lapping they could not be lapping
Perfect
I could not have lapped you could not have lapped he could not have lapped we could not have lapped you could not have lapped they could not have lapped
V-ing perfect
I could not have been lapping you could not have been lapping he could not have been lapping we could not have been lapping you could not have been lapping they could not 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
could I not lap? could you not lap? could he not lap? could we not lap? could you not lap? could they not lap?
V-ing form
could I not be lapping? could you not be lapping? could he not be lapping? could we not be lapping? could you not be lapping? could they not be lapping?
Perfect
could I not have lapped? could you not have lapped? could he not have lapped? could we not have lapped? could you not have lapped? could they not have lapped?
V-ing perfect
could I not have been lapping? could you not have been lapping? could he not have been lapping? could we not have been lapping? could you not have been lapping? could they not have been lapping?