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 couldn't blur you couldn't blur she couldn't blur we couldn't blur you couldn't blur they couldn't blur
V-ing form
I couldn't be blurring you couldn't be blurring she couldn't be blurring we couldn't be blurring you couldn't be blurring they couldn't be blurring
Perfect
I couldn't have blurred you couldn't have blurred she couldn't have blurred we couldn't have blurred you couldn't have blurred they couldn't have blurred
V-ing perfect
I couldn't have been blurring you couldn't have been blurring she couldn't have been blurring we couldn't have been blurring you couldn't have been blurring they couldn't 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
couldn't I blur? couldn't you blur? couldn't she blur? couldn't we blur? couldn't you blur? couldn't they blur?
V-ing form
couldn't I be blurring? couldn't you be blurring? couldn't she be blurring? couldn't we be blurring? couldn't you be blurring? couldn't they be blurring?
Perfect
couldn't I have blurred? couldn't you have blurred? couldn't she have blurred? couldn't we have blurred? couldn't you have blurred? couldn't they have blurred?
V-ing perfect
couldn't I have been blurring? couldn't you have been blurring? couldn't she have been blurring? couldn't we have been blurring? couldn't you have been blurring? couldn't they have been blurring?