English verb conjugation
COULD STOP

Regular verb: stop - stopped - stopped

Affirmation

Simple form	V-ing form
I could stop you could stop she could stop we could stop you could stop they could stop	I could be stopping you could be stopping she could be stopping we could be stopping you could be stopping they could be stopping
Perfect	V-ing perfect
I could have stopped you could have stopped she could have stopped we could have stopped you could have stopped they could have stopped	I could have been stopping you could have been stopping she could have been stopping we could have been stopping you could have been stopping they could have been stopping

Negation

Simple form	V-ing form
I couldn't stop you couldn't stop she couldn't stop we couldn't stop you couldn't stop they couldn't stop	I couldn't be stopping you couldn't be stopping she couldn't be stopping we couldn't be stopping you couldn't be stopping they couldn't be stopping
Perfect	V-ing perfect
I couldn't have stopped you couldn't have stopped she couldn't have stopped we couldn't have stopped you couldn't have stopped they couldn't have stopped	I couldn't have been stopping you couldn't have been stopping she couldn't have been stopping we couldn't have been stopping you couldn't have been stopping they couldn't have been stopping

Interrogative form

Simple form	V-ing form
could I stop? could you stop? could she stop? could we stop? could you stop? could they stop?	could I be stopping? could you be stopping? could she be stopping? could we be stopping? could you be stopping? could they be stopping?
Perfect	V-ing perfect
could I have stopped? could you have stopped? could she have stopped? could we have stopped? could you have stopped? could they have stopped?	could I have been stopping? could you have been stopping? could she have been stopping? could we have been stopping? could you have been stopping? could they have been stopping?

Interro-negative form

Simple form	V-ing form
couldn't I stop? couldn't you stop? couldn't she stop? couldn't we stop? couldn't you stop? couldn't they stop?	couldn't I be stopping? couldn't you be stopping? couldn't she be stopping? couldn't we be stopping? couldn't you be stopping? couldn't they be stopping?
Perfect	V-ing perfect
couldn't I have stopped? couldn't you have stopped? couldn't she have stopped? couldn't we have stopped? couldn't you have stopped? couldn't they have stopped?	couldn't I have been stopping? couldn't you have been stopping? couldn't she have been stopping? couldn't we have been stopping? couldn't you have been stopping? couldn't they have been stopping?