I could blur you could blur she could blur we could blur you could blur they could blur
V-ing form
I could be blurring you could be blurring she could be blurring we could be blurring you could be blurring they could be blurring
Perfect
I could have blurred you could have blurred she could have blurred we could have blurred you could have blurred they could have blurred
V-ing perfect
I could have been blurring you could have been blurring she could have been blurring we could have been blurring you could have been blurring they could have been blurring
Negation
Simple form
I could not blur you could not blur she could not blur we could not blur you could not blur they could not blur
V-ing form
I could not be blurring you could not be blurring she could not be blurring we could not be blurring you could not be blurring they could not be blurring
Perfect
I could not have blurred you could not have blurred she could not have blurred we could not have blurred you could not have blurred they could not have blurred
V-ing perfect
I could not have been blurring you could not have been blurring she could not have been blurring we could not have been blurring you could not have been blurring they could not have been blurring
Interrogative form
Simple form
could I blur? could you blur? could she blur? could we blur? could you blur? could they blur?
V-ing form
could I be blurring? could you be blurring? could she be blurring? could we be blurring? could you be blurring? could they be blurring?
Perfect
could I have blurred? could you have blurred? could she have blurred? could we have blurred? could you have blurred? could they have blurred?
V-ing perfect
could I have been blurring? could you have been blurring? could she have been blurring? could we have been blurring? could you have been blurring? could they have been blurring?
Interro-negative form
Simple form
could I not blur? could you not blur? could she not blur? could we not blur? could you not blur? could they not blur?
V-ing form
could I not be blurring? could you not be blurring? could she not be blurring? could we not be blurring? could you not be blurring? could they not be blurring?
Perfect
could I not have blurred? could you not have blurred? could she not have blurred? could we not have blurred? could you not have blurred? could they not have blurred?
V-ing perfect
could I not have been blurring? could you not have been blurring? could she not have been blurring? could we not have been blurring? could you not have been blurring? could they not have been blurring?