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