English verb conjugation
COULD BUTTER

Regular verb: butter - buttered - buttered

Affirmation

Simple form	V-ing form
I could butter you could butter he could butter we could butter you could butter they could butter	I could be buttering you could be buttering he 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 he 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 he 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 couldn't butter you couldn't butter he couldn't butter we couldn't butter you couldn't butter they couldn't butter	I couldn't be buttering you couldn't be buttering he couldn't be buttering we couldn't be buttering you couldn't be buttering they couldn't be buttering
Perfect	V-ing perfect
I couldn't have buttered you couldn't have buttered he couldn't have buttered we couldn't have buttered you couldn't have buttered they couldn't have buttered	I couldn't have been buttering you couldn't have been buttering he couldn't have been buttering we couldn't have been buttering you couldn't have been buttering they couldn't have been buttering

Interrogative form

Simple form	V-ing form
could I butter? could you butter? could he butter? could we butter? could you butter? could they butter?	could I be buttering? could you be buttering? could he 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 he 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 he 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
couldn't I butter? couldn't you butter? couldn't he butter? couldn't we butter? couldn't you butter? couldn't they butter?	couldn't I be buttering? couldn't you be buttering? couldn't he be buttering? couldn't we be buttering? couldn't you be buttering? couldn't they be buttering?
Perfect	V-ing perfect
couldn't I have buttered? couldn't you have buttered? couldn't he have buttered? couldn't we have buttered? couldn't you have buttered? couldn't they have buttered?	couldn't I have been buttering? couldn't you have been buttering? couldn't he have been buttering? couldn't we have been buttering? couldn't you have been buttering? couldn't they have been buttering?