English verb conjugation
COULD DOUBLE-BILL

Regular verb: double-bill - double-billed - double-billed

Affirmation

Simple form	V-ing form
I could double-bill you could double-bill he could double-bill we could double-bill you could double-bill they could double-bill	I could be double-billing you could be double-billing he could be double-billing we could be double-billing you could be double-billing they could be double-billing
Perfect	V-ing perfect
I could have double-billed you could have double-billed he could have double-billed we could have double-billed you could have double-billed they could have double-billed	I could have been double-billing you could have been double-billing he could have been double-billing we could have been double-billing you could have been double-billing they could have been double-billing

Negation

Simple form	V-ing form
I could not double-bill you could not double-bill he could not double-bill we could not double-bill you could not double-bill they could not double-bill	I could not be double-billing you could not be double-billing he could not be double-billing we could not be double-billing you could not be double-billing they could not be double-billing
Perfect	V-ing perfect
I could not have double-billed you could not have double-billed he could not have double-billed we could not have double-billed you could not have double-billed they could not have double-billed	I could not have been double-billing you could not have been double-billing he could not have been double-billing we could not have been double-billing you could not have been double-billing they could not have been double-billing

Interrogative form

Simple form	V-ing form
could I double-bill? could you double-bill? could he double-bill? could we double-bill? could you double-bill? could they double-bill?	could I be double-billing? could you be double-billing? could he be double-billing? could we be double-billing? could you be double-billing? could they be double-billing?
Perfect	V-ing perfect
could I have double-billed? could you have double-billed? could he have double-billed? could we have double-billed? could you have double-billed? could they have double-billed?	could I have been double-billing? could you have been double-billing? could he have been double-billing? could we have been double-billing? could you have been double-billing? could they have been double-billing?

Interro-negative form

Simple form	V-ing form
could I not double-bill? could you not double-bill? could he not double-bill? could we not double-bill? could you not double-bill? could they not double-bill?	could I not be double-billing? could you not be double-billing? could he not be double-billing? could we not be double-billing? could you not be double-billing? could they not be double-billing?
Perfect	V-ing perfect
could I not have double-billed? could you not have double-billed? could he not have double-billed? could we not have double-billed? could you not have double-billed? could they not have double-billed?	could I not have been double-billing? could you not have been double-billing? could he not have been double-billing? could we not have been double-billing? could you not have been double-billing? could they not have been double-billing?