I could don you could don she could don we could don you could don they could don
V-ing form
I could be donning you could be donning she could be donning we could be donning you could be donning they could be donning
Perfect
I could have donned you could have donned she could have donned we could have donned you could have donned they could have donned
V-ing perfect
I could have been donning you could have been donning she could have been donning we could have been donning you could have been donning they could have been donning
Negation
Simple form
I couldn't don you couldn't don she couldn't don we couldn't don you couldn't don they couldn't don
V-ing form
I couldn't be donning you couldn't be donning she couldn't be donning we couldn't be donning you couldn't be donning they couldn't be donning
Perfect
I couldn't have donned you couldn't have donned she couldn't have donned we couldn't have donned you couldn't have donned they couldn't have donned
V-ing perfect
I couldn't have been donning you couldn't have been donning she couldn't have been donning we couldn't have been donning you couldn't have been donning they couldn't have been donning
Interrogative form
Simple form
could I don? could you don? could she don? could we don? could you don? could they don?
V-ing form
could I be donning? could you be donning? could she be donning? could we be donning? could you be donning? could they be donning?
Perfect
could I have donned? could you have donned? could she have donned? could we have donned? could you have donned? could they have donned?
V-ing perfect
could I have been donning? could you have been donning? could she have been donning? could we have been donning? could you have been donning? could they have been donning?
Interro-negative form
Simple form
couldn't I don? couldn't you don? couldn't she don? couldn't we don? couldn't you don? couldn't they don?
V-ing form
couldn't I be donning? couldn't you be donning? couldn't she be donning? couldn't we be donning? couldn't you be donning? couldn't they be donning?
Perfect
couldn't I have donned? couldn't you have donned? couldn't she have donned? couldn't we have donned? couldn't you have donned? couldn't they have donned?
V-ing perfect
couldn't I have been donning? couldn't you have been donning? couldn't she have been donning? couldn't we have been donning? couldn't you have been donning? couldn't they have been donning?