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