English verb conjugation
COULD QUADRUPLE

Regular verb: quadruple - quadrupled - quadrupled

Affirmation

Simple form	V-ing form
I could quadruple you could quadruple he could quadruple we could quadruple you could quadruple they could quadruple	I could be quadrupling you could be quadrupling he could be quadrupling we could be quadrupling you could be quadrupling they could be quadrupling
Perfect	V-ing perfect
I could have quadrupled you could have quadrupled he could have quadrupled we could have quadrupled you could have quadrupled they could have quadrupled	I could have been quadrupling you could have been quadrupling he could have been quadrupling we could have been quadrupling you could have been quadrupling they could have been quadrupling

Negation

Simple form	V-ing form
I couldn't quadruple you couldn't quadruple he couldn't quadruple we couldn't quadruple you couldn't quadruple they couldn't quadruple	I couldn't be quadrupling you couldn't be quadrupling he couldn't be quadrupling we couldn't be quadrupling you couldn't be quadrupling they couldn't be quadrupling
Perfect	V-ing perfect
I couldn't have quadrupled you couldn't have quadrupled he couldn't have quadrupled we couldn't have quadrupled you couldn't have quadrupled they couldn't have quadrupled	I couldn't have been quadrupling you couldn't have been quadrupling he couldn't have been quadrupling we couldn't have been quadrupling you couldn't have been quadrupling they couldn't have been quadrupling

Interrogative form

Simple form	V-ing form
could I quadruple? could you quadruple? could he quadruple? could we quadruple? could you quadruple? could they quadruple?	could I be quadrupling? could you be quadrupling? could he be quadrupling? could we be quadrupling? could you be quadrupling? could they be quadrupling?
Perfect	V-ing perfect
could I have quadrupled? could you have quadrupled? could he have quadrupled? could we have quadrupled? could you have quadrupled? could they have quadrupled?	could I have been quadrupling? could you have been quadrupling? could he have been quadrupling? could we have been quadrupling? could you have been quadrupling? could they have been quadrupling?

Interro-negative form

Simple form	V-ing form
couldn't I quadruple? couldn't you quadruple? couldn't he quadruple? couldn't we quadruple? couldn't you quadruple? couldn't they quadruple?	couldn't I be quadrupling? couldn't you be quadrupling? couldn't he be quadrupling? couldn't we be quadrupling? couldn't you be quadrupling? couldn't they be quadrupling?
Perfect	V-ing perfect
couldn't I have quadrupled? couldn't you have quadrupled? couldn't he have quadrupled? couldn't we have quadrupled? couldn't you have quadrupled? couldn't they have quadrupled?	couldn't I have been quadrupling? couldn't you have been quadrupling? couldn't he have been quadrupling? couldn't we have been quadrupling? couldn't you have been quadrupling? couldn't they have been quadrupling?