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 couldn't double-bill you couldn't double-bill he couldn't double-bill we couldn't double-bill you couldn't double-bill they couldn't double-bill	I couldn't be double-billing you couldn't be double-billing he couldn't be double-billing we couldn't be double-billing you couldn't be double-billing they couldn't be double-billing
Perfect	V-ing perfect
I couldn't have double-billed you couldn't have double-billed he couldn't have double-billed we couldn't have double-billed you couldn't have double-billed they couldn't have double-billed	I couldn't have been double-billing you couldn't have been double-billing he couldn't have been double-billing we couldn't have been double-billing you couldn't have been double-billing they couldn't 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
couldn't I double-bill? couldn't you double-bill? couldn't he double-bill? couldn't we double-bill? couldn't you double-bill? couldn't they double-bill?	couldn't I be double-billing? couldn't you be double-billing? couldn't he be double-billing? couldn't we be double-billing? couldn't you be double-billing? couldn't they be double-billing?
Perfect	V-ing perfect
couldn't I have double-billed? couldn't you have double-billed? couldn't he have double-billed? couldn't we have double-billed? couldn't you have double-billed? couldn't they have double-billed?	couldn't I have been double-billing? couldn't you have been double-billing? couldn't he have been double-billing? couldn't we have been double-billing? couldn't you have been double-billing? couldn't they have been double-billing?