English verb conjugation
COULD FROST

Regular verb: frost - frosted - frosted

Affirmation

Simple form	V-ing form
I could frost you could frost he could frost we could frost you could frost they could frost	I could be frosting you could be frosting he 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 he 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 he 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 he 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 he 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 he 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 he 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 he frost? could we frost? could you frost? could they frost?	could I be frosting? could you be frosting? could he 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 he 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 he 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 he 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 he 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 he 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 he not have been frosting? could we not have been frosting? could you not have been frosting? could they not have been frosting?