could butter
Regular verb: butter - buttered- buttered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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	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 	Perfect 	V-ing perfect 	
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	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 	Perfect 	V-ing perfect 	
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? 	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 	Perfect 	V-ing perfect 	
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? 	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?