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 could not unfasten you could not unfasten he could not unfasten we could not unfasten you could not unfasten they could not unfasten	I could not be unfastening you could not be unfastening he could not be unfastening we could not be unfastening you could not be unfastening they could not be unfastening
Perfect	V-ing perfect
I could not have unfastened you could not have unfastened he could not have unfastened we could not have unfastened you could not have unfastened they could not have unfastened	I could not have been unfastening you could not have been unfastening he could not have been unfastening we could not have been unfastening you could not have been unfastening they could not 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
could I not unfasten? could you not unfasten? could he not unfasten? could we not unfasten? could you not unfasten? could they not unfasten?	could I not be unfastening? could you not be unfastening? could he not be unfastening? could we not be unfastening? could you not be unfastening? could they not be unfastening?
Perfect	V-ing perfect
could I not have unfastened? could you not have unfastened? could he not have unfastened? could we not have unfastened? could you not have unfastened? could they not have unfastened?	could I not have been unfastening? could you not have been unfastening? could he not have been unfastening? could we not have been unfastening? could you not have been unfastening? could they not have been unfastening?