English verb conjugation
COULD UNFASTEN

Regular verb: unfasten - unfastened - unfastened

Affirmation

Simple form	V-ing form
I could unfasten you could unfasten he could unfasten we could unfasten you could unfasten they could unfasten	I could be unfastening you could be unfastening he could be unfastening we could be unfastening you could be unfastening they could be unfastening
Perfect	V-ing perfect
I could have unfastened you could have unfastened he could have unfastened we could have unfastened you could have unfastened they could have unfastened	I could have been unfastening you could have been unfastening he could have been unfastening we could have been unfastening you could have been unfastening they could have been unfastening

Negation

Simple form	V-ing form
I couldn't unfasten you couldn't unfasten he couldn't unfasten we couldn't unfasten you couldn't unfasten they couldn't unfasten	I couldn't be unfastening you couldn't be unfastening he couldn't be unfastening we couldn't be unfastening you couldn't be unfastening they couldn't be unfastening
Perfect	V-ing perfect
I couldn't have unfastened you couldn't have unfastened he couldn't have unfastened we couldn't have unfastened you couldn't have unfastened they couldn't have unfastened	I couldn't have been unfastening you couldn't have been unfastening he couldn't have been unfastening we couldn't have been unfastening you couldn't have been unfastening they couldn't have been unfastening

Interrogative form

Simple form	V-ing form
could I unfasten? could you unfasten? could he unfasten? could we unfasten? could you unfasten? could they unfasten?	could I be unfastening? could you be unfastening? could he be unfastening? could we be unfastening? could you be unfastening? could they be unfastening?
Perfect	V-ing perfect
could I have unfastened? could you have unfastened? could he have unfastened? could we have unfastened? could you have unfastened? could they have unfastened?	could I have been unfastening? could you have been unfastening? could he have been unfastening? could we have been unfastening? could you have been unfastening? could they have been unfastening?

Interro-negative form

Simple form	V-ing form
couldn't I unfasten? couldn't you unfasten? couldn't he unfasten? couldn't we unfasten? couldn't you unfasten? couldn't they unfasten?	couldn't I be unfastening? couldn't you be unfastening? couldn't he be unfastening? couldn't we be unfastening? couldn't you be unfastening? couldn't they be unfastening?
Perfect	V-ing perfect
couldn't I have unfastened? couldn't you have unfastened? couldn't he have unfastened? couldn't we have unfastened? couldn't you have unfastened? couldn't they have unfastened?	couldn't I have been unfastening? couldn't you have been unfastening? couldn't he have been unfastening? couldn't we have been unfastening? couldn't you have been unfastening? couldn't they have been unfastening?