English verb conjugation
COULD ABSTAIN

Regular verb: abstain - abstained - abstained

Affirmation

Simple form	V-ing form
I could abstain you could abstain he could abstain we could abstain you could abstain they could abstain	I could be abstaining you could be abstaining he could be abstaining we could be abstaining you could be abstaining they could be abstaining
Perfect	V-ing perfect
I could have abstained you could have abstained he could have abstained we could have abstained you could have abstained they could have abstained	I could have been abstaining you could have been abstaining he could have been abstaining we could have been abstaining you could have been abstaining they could have been abstaining

Negation

Simple form	V-ing form
I couldn't abstain you couldn't abstain he couldn't abstain we couldn't abstain you couldn't abstain they couldn't abstain	I couldn't be abstaining you couldn't be abstaining he couldn't be abstaining we couldn't be abstaining you couldn't be abstaining they couldn't be abstaining
Perfect	V-ing perfect
I couldn't have abstained you couldn't have abstained he couldn't have abstained we couldn't have abstained you couldn't have abstained they couldn't have abstained	I couldn't have been abstaining you couldn't have been abstaining he couldn't have been abstaining we couldn't have been abstaining you couldn't have been abstaining they couldn't have been abstaining

Interrogative form

Simple form	V-ing form
could I abstain? could you abstain? could he abstain? could we abstain? could you abstain? could they abstain?	could I be abstaining? could you be abstaining? could he be abstaining? could we be abstaining? could you be abstaining? could they be abstaining?
Perfect	V-ing perfect
could I have abstained? could you have abstained? could he have abstained? could we have abstained? could you have abstained? could they have abstained?	could I have been abstaining? could you have been abstaining? could he have been abstaining? could we have been abstaining? could you have been abstaining? could they have been abstaining?

Interro-negative form

Simple form	V-ing form
couldn't I abstain? couldn't you abstain? couldn't he abstain? couldn't we abstain? couldn't you abstain? couldn't they abstain?	couldn't I be abstaining? couldn't you be abstaining? couldn't he be abstaining? couldn't we be abstaining? couldn't you be abstaining? couldn't they be abstaining?
Perfect	V-ing perfect
couldn't I have abstained? couldn't you have abstained? couldn't he have abstained? couldn't we have abstained? couldn't you have abstained? couldn't they have abstained?	couldn't I have been abstaining? couldn't you have been abstaining? couldn't he have been abstaining? couldn't we have been abstaining? couldn't you have been abstaining? couldn't they have been abstaining?