I could taw you could taw she could taw we could taw you could taw they could taw
V-ing form
I could be tawing you could be tawing she could be tawing we could be tawing you could be tawing they could be tawing
Perfect
I could have tawed you could have tawed she could have tawed we could have tawed you could have tawed they could have tawed
V-ing perfect
I could have been tawing you could have been tawing she could have been tawing we could have been tawing you could have been tawing they could have been tawing
Negation
Simple form
I could not taw you could not taw she could not taw we could not taw you could not taw they could not taw
V-ing form
I could not be tawing you could not be tawing she could not be tawing we could not be tawing you could not be tawing they could not be tawing
Perfect
I could not have tawed you could not have tawed she could not have tawed we could not have tawed you could not have tawed they could not have tawed
V-ing perfect
I could not have been tawing you could not have been tawing she could not have been tawing we could not have been tawing you could not have been tawing they could not have been tawing
Interrogative form
Simple form
could I taw? could you taw? could she taw? could we taw? could you taw? could they taw?
V-ing form
could I be tawing? could you be tawing? could she be tawing? could we be tawing? could you be tawing? could they be tawing?
Perfect
could I have tawed? could you have tawed? could she have tawed? could we have tawed? could you have tawed? could they have tawed?
V-ing perfect
could I have been tawing? could you have been tawing? could she have been tawing? could we have been tawing? could you have been tawing? could they have been tawing?
Interro-negative form
Simple form
could I not taw? could you not taw? could she not taw? could we not taw? could you not taw? could they not taw?
V-ing form
could I not be tawing? could you not be tawing? could she not be tawing? could we not be tawing? could you not be tawing? could they not be tawing?
Perfect
could I not have tawed? could you not have tawed? could she not have tawed? could we not have tawed? could you not have tawed? could they not have tawed?
V-ing perfect
could I not have been tawing? could you not have been tawing? could she not have been tawing? could we not have been tawing? could you not have been tawing? could they not have been tawing?