English verb conjugation
COULD PROOF

Regular verb: proof - proofed - proofed

Affirmation

Simple form	V-ing form
I could proof you could proof he could proof we could proof you could proof they could proof	I could be proofing you could be proofing he could be proofing we could be proofing you could be proofing they could be proofing
Perfect	V-ing perfect
I could have proofed you could have proofed he could have proofed we could have proofed you could have proofed they could have proofed	I could have been proofing you could have been proofing he could have been proofing we could have been proofing you could have been proofing they could have been proofing

Negation

Simple form	V-ing form
I couldn't proof you couldn't proof he couldn't proof we couldn't proof you couldn't proof they couldn't proof	I couldn't be proofing you couldn't be proofing he couldn't be proofing we couldn't be proofing you couldn't be proofing they couldn't be proofing
Perfect	V-ing perfect
I couldn't have proofed you couldn't have proofed he couldn't have proofed we couldn't have proofed you couldn't have proofed they couldn't have proofed	I couldn't have been proofing you couldn't have been proofing he 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	V-ing form
could I proof? could you proof? could he proof? could we proof? could you proof? could they proof?	could I be proofing? could you be proofing? could he be proofing? could we be proofing? could you be proofing? could they be proofing?
Perfect	V-ing perfect
could I have proofed? could you have proofed? could he have proofed? could we have proofed? could you have proofed? could they have proofed?	could I have been proofing? could you have been proofing? could he have been proofing? could we have been proofing? could you have been proofing? could they have been proofing?

Interro-negative form

Simple form	V-ing form
couldn't I proof? couldn't you proof? couldn't he proof? couldn't we proof? couldn't you proof? couldn't they proof?	couldn't I be proofing? couldn't you be proofing? couldn't he be proofing? couldn't we be proofing? couldn't you be proofing? couldn't they be proofing?
Perfect	V-ing perfect
couldn't I have proofed? couldn't you have proofed? couldn't he have proofed? couldn't we have proofed? couldn't you have proofed? couldn't they have proofed?	couldn't I have been proofing? couldn't you have been proofing? couldn't he have been proofing? couldn't we have been proofing? couldn't you have been proofing? couldn't they have been proofing?