must quadruple
Regular verb: quadruple - quadrupled- quadrupled

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

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not quadruple
you must not quadruple
he must not quadruple
we must not quadruple
you must not quadruple
they must not quadruple 	I must not be quadrupling
you must not be quadrupling
he must not be quadrupling
we must not be quadrupling
you must not be quadrupling
they must not be quadrupling	I must not have quadrupled
you must not have quadrupled
he must not have quadrupled
we must not have quadrupled
you must not have quadrupled
they must not have quadrupled	I must not have been quadrupling
you must not have been quadrupling
he must not have been quadrupling
we must not have been quadrupling
you must not have been quadrupling
they must not have been quadrupling	

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

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not quadruple?
must you not quadruple?
must he not quadruple?
must we not quadruple?
must you not quadruple?
must they not quadruple? 	must I not be quadrupling?
must you not be quadrupling?
must he not be quadrupling?
must we not be quadrupling?
must you not be quadrupling?
must they not be quadrupling? 	must I not have quadrupled?
must you not have quadrupled?
must he not have quadrupled?
must we not have quadrupled?
must you not have quadrupled?
must they not have quadrupled? 	must I not have been quadrupling?
must you not have been quadrupling?
must he not have been quadrupling?
must we not have been quadrupling?
must you not have been quadrupling?
must they not have been quadrupling?