can quadruple
Regular verb: quadruple - quadrupled- quadrupled

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