English verb conjugation
COULD UNSCREW

Regular verb: unscrew - unscrewed - unscrewed

Affirmation

Simple form	V-ing form
I could unscrew you could unscrew she could unscrew we could unscrew you could unscrew they could unscrew	I could be unscrewing you could be unscrewing she could be unscrewing we could be unscrewing you could be unscrewing they could be unscrewing
Perfect	V-ing perfect
I could have unscrewed you could have unscrewed she could have unscrewed we could have unscrewed you could have unscrewed they could have unscrewed	I could have been unscrewing you could have been unscrewing she could have been unscrewing we could have been unscrewing you could have been unscrewing they could have been unscrewing

Negation

Simple form	V-ing form
I couldn't unscrew you couldn't unscrew she couldn't unscrew we couldn't unscrew you couldn't unscrew they couldn't unscrew	I couldn't be unscrewing you couldn't be unscrewing she couldn't be unscrewing we couldn't be unscrewing you couldn't be unscrewing they couldn't be unscrewing
Perfect	V-ing perfect
I couldn't have unscrewed you couldn't have unscrewed she couldn't have unscrewed we couldn't have unscrewed you couldn't have unscrewed they couldn't have unscrewed	I couldn't have been unscrewing you couldn't have been unscrewing she couldn't have been unscrewing we couldn't have been unscrewing you couldn't have been unscrewing they couldn't have been unscrewing

Interrogative form

Simple form	V-ing form
could I unscrew? could you unscrew? could she unscrew? could we unscrew? could you unscrew? could they unscrew?	could I be unscrewing? could you be unscrewing? could she be unscrewing? could we be unscrewing? could you be unscrewing? could they be unscrewing?
Perfect	V-ing perfect
could I have unscrewed? could you have unscrewed? could she have unscrewed? could we have unscrewed? could you have unscrewed? could they have unscrewed?	could I have been unscrewing? could you have been unscrewing? could she have been unscrewing? could we have been unscrewing? could you have been unscrewing? could they have been unscrewing?

Interro-negative form

Simple form	V-ing form
couldn't I unscrew? couldn't you unscrew? couldn't she unscrew? couldn't we unscrew? couldn't you unscrew? couldn't they unscrew?	couldn't I be unscrewing? couldn't you be unscrewing? couldn't she be unscrewing? couldn't we be unscrewing? couldn't you be unscrewing? couldn't they be unscrewing?
Perfect	V-ing perfect
couldn't I have unscrewed? couldn't you have unscrewed? couldn't she have unscrewed? couldn't we have unscrewed? couldn't you have unscrewed? couldn't they have unscrewed?	couldn't I have been unscrewing? couldn't you have been unscrewing? couldn't she have been unscrewing? couldn't we have been unscrewing? couldn't you have been unscrewing? couldn't they have been unscrewing?