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