English verb conjugation
COULD FROST

Regular verb: frost - frosted - frosted

Affirmation

Simple form	V-ing form
I could frost you could frost she could frost we could frost you could frost they could frost	I could be frosting you could be frosting she could be frosting we could be frosting you could be frosting they could be frosting
Perfect	V-ing perfect
I could have frosted you could have frosted she could have frosted we could have frosted you could have frosted they could have frosted	I could have been frosting you could have been frosting she could have been frosting we could have been frosting you could have been frosting they could have been frosting

Negation

Simple form	V-ing form
I could not frost you could not frost she could not frost we could not frost you could not frost they could not frost	I could not be frosting you could not be frosting she could not be frosting we could not be frosting you could not be frosting they could not be frosting
Perfect	V-ing perfect
I could not have frosted you could not have frosted she could not have frosted we could not have frosted you could not have frosted they could not have frosted	I could not have been frosting you could not have been frosting she could not have been frosting we could not have been frosting you could not have been frosting they could not have been frosting

Interrogative form

Simple form	V-ing form
could I frost? could you frost? could she frost? could we frost? could you frost? could they frost?	could I be frosting? could you be frosting? could she be frosting? could we be frosting? could you be frosting? could they be frosting?
Perfect	V-ing perfect
could I have frosted? could you have frosted? could she have frosted? could we have frosted? could you have frosted? could they have frosted?	could I have been frosting? could you have been frosting? could she have been frosting? could we have been frosting? could you have been frosting? could they have been frosting?

Interro-negative form

Simple form	V-ing form
could I not frost? could you not frost? could she not frost? could we not frost? could you not frost? could they not frost?	could I not be frosting? could you not be frosting? could she not be frosting? could we not be frosting? could you not be frosting? could they not be frosting?
Perfect	V-ing perfect
could I not have frosted? could you not have frosted? could she not have frosted? could we not have frosted? could you not have frosted? could they not have frosted?	could I not have been frosting? could you not have been frosting? could she not have been frosting? could we not have been frosting? could you not have been frosting? could they not have been frosting?