English verb conjugation
COULD STOPPER

Regular verb: stopper - stoppered - stoppered

Affirmation

Simple form	V-ing form
I could stopper you could stopper she could stopper we could stopper you could stopper they could stopper	I could be stoppering you could be stoppering she could be stoppering we could be stoppering you could be stoppering they could be stoppering
Perfect	V-ing perfect
I could have stoppered you could have stoppered she could have stoppered we could have stoppered you could have stoppered they could have stoppered	I could have been stoppering you could have been stoppering she could have been stoppering we could have been stoppering you could have been stoppering they could have been stoppering

Negation

Simple form	V-ing form
I couldn't stopper you couldn't stopper she couldn't stopper we couldn't stopper you couldn't stopper they couldn't stopper	I couldn't be stoppering you couldn't be stoppering she couldn't be stoppering we couldn't be stoppering you couldn't be stoppering they couldn't be stoppering
Perfect	V-ing perfect
I couldn't have stoppered you couldn't have stoppered she couldn't have stoppered we couldn't have stoppered you couldn't have stoppered they couldn't have stoppered	I couldn't have been stoppering you couldn't have been stoppering she couldn't have been stoppering we couldn't have been stoppering you couldn't have been stoppering they couldn't have been stoppering

Interrogative form

Simple form	V-ing form
could I stopper? could you stopper? could she stopper? could we stopper? could you stopper? could they stopper?	could I be stoppering? could you be stoppering? could she be stoppering? could we be stoppering? could you be stoppering? could they be stoppering?
Perfect	V-ing perfect
could I have stoppered? could you have stoppered? could she have stoppered? could we have stoppered? could you have stoppered? could they have stoppered?	could I have been stoppering? could you have been stoppering? could she have been stoppering? could we have been stoppering? could you have been stoppering? could they have been stoppering?

Interro-negative form

Simple form	V-ing form
couldn't I stopper? couldn't you stopper? couldn't she stopper? couldn't we stopper? couldn't you stopper? couldn't they stopper?	couldn't I be stoppering? couldn't you be stoppering? couldn't she be stoppering? couldn't we be stoppering? couldn't you be stoppering? couldn't they be stoppering?
Perfect	V-ing perfect
couldn't I have stoppered? couldn't you have stoppered? couldn't she have stoppered? couldn't we have stoppered? couldn't you have stoppered? couldn't they have stoppered?	couldn't I have been stoppering? couldn't you have been stoppering? couldn't she have been stoppering? couldn't we have been stoppering? couldn't you have been stoppering? couldn't they have been stoppering?