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