I could shave you could shave she could shave we could shave you could shave they could shave
V-ing form
I could be shaving you could be shaving she could be shaving we could be shaving you could be shaving they could be shaving
Perfect
I could have shaven, shaved you could have shaven, shaved she could have shaven, shaved we could have shaven, shaved you could have shaven, shaved they could have shaven, shaved
V-ing perfect
I could have been shaving you could have been shaving she could have been shaving we could have been shaving you could have been shaving they could have been shaving
Negation
Simple form
I couldn't shave you couldn't shave she couldn't shave we couldn't shave you couldn't shave they couldn't shave
V-ing form
I couldn't be shaving you couldn't be shaving she couldn't be shaving we couldn't be shaving you couldn't be shaving they couldn't be shaving
Perfect
I couldn't have shaven, shaved you couldn't have shaven, shaved she couldn't have shaven, shaved we couldn't have shaven, shaved you couldn't have shaven, shaved they couldn't have shaven, shaved
V-ing perfect
I couldn't have been shaving you couldn't have been shaving she couldn't have been shaving we couldn't have been shaving you couldn't have been shaving they couldn't have been shaving
Interrogative form
Simple form
could I shave? could you shave? could she shave? could we shave? could you shave? could they shave?
V-ing form
could I be shaving? could you be shaving? could she be shaving? could we be shaving? could you be shaving? could they be shaving?
Perfect
could I have shaven, shaved? could you have shaven, shaved? could she have shaven, shaved? could we have shaven, shaved? could you have shaven, shaved? could they have shaven, shaved?
V-ing perfect
could I have been shaving? could you have been shaving? could she have been shaving? could we have been shaving? could you have been shaving? could they have been shaving?
Interro-negative form
Simple form
couldn't I shave? couldn't you shave? couldn't she shave? couldn't we shave? couldn't you shave? couldn't they shave?
V-ing form
couldn't I be shaving? couldn't you be shaving? couldn't she be shaving? couldn't we be shaving? couldn't you be shaving? couldn't they be shaving?
Perfect
couldn't I have shaven, shaved? couldn't you have shaven, shaved? couldn't she have shaven, shaved? couldn't we have shaven, shaved? couldn't you have shaven, shaved? couldn't they have shaven, shaved?
V-ing perfect
couldn't I have been shaving? couldn't you have been shaving? couldn't she have been shaving? couldn't we have been shaving? couldn't you have been shaving? couldn't they have been shaving?