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