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