I can quadruple you can quadruple he can quadruple we can quadruple you can quadruple they can quadruple
V-ing form
I can be quadrupling you can be quadrupling he can be quadrupling we can be quadrupling you can be quadrupling they can be quadrupling
Perfect
I can have quadrupled you can have quadrupled he can have quadrupled we can have quadrupled you can have quadrupled they can have quadrupled
V-ing perfect
I can have been quadrupling you can have been quadrupling he can have been quadrupling we can have been quadrupling you can have been quadrupling they can have been quadrupling
Negation
Simple form
I can't quadruple you can't quadruple he can't quadruple we can't quadruple you can't quadruple they can't quadruple
V-ing form
I can't be quadrupling you can't be quadrupling he can't be quadrupling we can't be quadrupling you can't be quadrupling they can't be quadrupling
Perfect
I can't have quadrupled you can't have quadrupled he can't have quadrupled we can't have quadrupled you can't have quadrupled they can't have quadrupled
V-ing perfect
I can't have been quadrupling you can't have been quadrupling he can't have been quadrupling we can't have been quadrupling you can't have been quadrupling they can't have been quadrupling
Interrogative form
Simple form
can I quadruple? can you quadruple? can he quadruple? can we quadruple? can you quadruple? can they quadruple?
V-ing form
can I be quadrupling? can you be quadrupling? can he be quadrupling? can we be quadrupling? can you be quadrupling? can they be quadrupling?
Perfect
can I have quadrupled? can you have quadrupled? can he have quadrupled? can we have quadrupled? can you have quadrupled? can they have quadrupled?
V-ing perfect
can I have been quadrupling? can you have been quadrupling? can he have been quadrupling? can we have been quadrupling? can you have been quadrupling? can they have been quadrupling?
Interro-negative form
Simple form
can't I quadruple? can't you quadruple? can't he quadruple? can't we quadruple? can't you quadruple? can't they quadruple?
V-ing form
can't I be quadrupling? can't you be quadrupling? can't he be quadrupling? can't we be quadrupling? can't you be quadrupling? can't they be quadrupling?
Perfect
can't I have quadrupled? can't you have quadrupled? can't he have quadrupled? can't we have quadrupled? can't you have quadrupled? can't they have quadrupled?
V-ing perfect
can't I have been quadrupling? can't you have been quadrupling? can't he have been quadrupling? can't we have been quadrupling? can't you have been quadrupling? can't they have been quadrupling?