English verb conjugation
COULD DOUBLE

Regular verb: double - doubled - doubled

Affirmation

Simple form	V-ing form
I could double you could double he could double we could double you could double they could double	I could be doubling you could be doubling he could be doubling we could be doubling you could be doubling they could be doubling
Perfect	V-ing perfect
I could have doubled you could have doubled he could have doubled we could have doubled you could have doubled they could have doubled	I could have been doubling you could have been doubling he could have been doubling we could have been doubling you could have been doubling they could have been doubling

Negation

Simple form	V-ing form
I could not double you could not double he could not double we could not double you could not double they could not double	I could not be doubling you could not be doubling he could not be doubling we could not be doubling you could not be doubling they could not be doubling
Perfect	V-ing perfect
I could not have doubled you could not have doubled he could not have doubled we could not have doubled you could not have doubled they could not have doubled	I could not have been doubling you could not have been doubling he could not have been doubling we could not have been doubling you could not have been doubling they could not have been doubling

Interrogative form

Simple form	V-ing form
could I double? could you double? could he double? could we double? could you double? could they double?	could I be doubling? could you be doubling? could he be doubling? could we be doubling? could you be doubling? could they be doubling?
Perfect	V-ing perfect
could I have doubled? could you have doubled? could he have doubled? could we have doubled? could you have doubled? could they have doubled?	could I have been doubling? could you have been doubling? could he have been doubling? could we have been doubling? could you have been doubling? could they have been doubling?

Interro-negative form

Simple form	V-ing form
could I not double? could you not double? could he not double? could we not double? could you not double? could they not double?	could I not be doubling? could you not be doubling? could he not be doubling? could we not be doubling? could you not be doubling? could they not be doubling?
Perfect	V-ing perfect
could I not have doubled? could you not have doubled? could he not have doubled? could we not have doubled? could you not have doubled? could they not have doubled?	could I not have been doubling? could you not have been doubling? could he not have been doubling? could we not have been doubling? could you not have been doubling? could they not have been doubling?