English verb conjugation
COULD BUTTER

Regular verb: butter - buttered - buttered

Affirmation

Simple form	V-ing form
I could butter you could butter she could butter we could butter you could butter they could butter	I could be buttering you could be buttering she could be buttering we could be buttering you could be buttering they could be buttering
Perfect	V-ing perfect
I could have buttered you could have buttered she could have buttered we could have buttered you could have buttered they could have buttered	I could have been buttering you could have been buttering she could have been buttering we could have been buttering you could have been buttering they could have been buttering

Negation

Simple form	V-ing form
I could not butter you could not butter she could not butter we could not butter you could not butter they could not butter	I could not be buttering you could not be buttering she could not be buttering we could not be buttering you could not be buttering they could not be buttering
Perfect	V-ing perfect
I could not have buttered you could not have buttered she could not have buttered we could not have buttered you could not have buttered they could not have buttered	I could not have been buttering you could not have been buttering she could not have been buttering we could not have been buttering you could not have been buttering they could not have been buttering

Interrogative form

Simple form	V-ing form
could I butter? could you butter? could she butter? could we butter? could you butter? could they butter?	could I be buttering? could you be buttering? could she be buttering? could we be buttering? could you be buttering? could they be buttering?
Perfect	V-ing perfect
could I have buttered? could you have buttered? could she have buttered? could we have buttered? could you have buttered? could they have buttered?	could I have been buttering? could you have been buttering? could she have been buttering? could we have been buttering? could you have been buttering? could they have been buttering?

Interro-negative form

Simple form	V-ing form
could I not butter? could you not butter? could she not butter? could we not butter? could you not butter? could they not butter?	could I not be buttering? could you not be buttering? could she not be buttering? could we not be buttering? could you not be buttering? could they not be buttering?
Perfect	V-ing perfect
could I not have buttered? could you not have buttered? could she not have buttered? could we not have buttered? could you not have buttered? could they not have buttered?	could I not have been buttering? could you not have been buttering? could she not have been buttering? could we not have been buttering? could you not have been buttering? could they not have been buttering?