must quintuple
Regular verb: quintuple - quintupled- quintupled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must quintuple
you must quintuple
he must quintuple
we must quintuple
you must quintuple
they must quintuple 	I must be quintupling
you must be quintupling
he must be quintupling
we must be quintupling
you must be quintupling
they must be quintupling	I must have quintupled
you must have quintupled
he must have quintupled
we must have quintupled
you must have quintupled
they must have quintupled	I must have been quintupling
you must have been quintupling
he must have been quintupling
we must have been quintupling
you must have been quintupling
they must have been quintupling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not quintuple
you must not quintuple
he must not quintuple
we must not quintuple
you must not quintuple
they must not quintuple 	I must not be quintupling
you must not be quintupling
he must not be quintupling
we must not be quintupling
you must not be quintupling
they must not be quintupling	I must not have quintupled
you must not have quintupled
he must not have quintupled
we must not have quintupled
you must not have quintupled
they must not have quintupled	I must not have been quintupling
you must not have been quintupling
he must not have been quintupling
we must not have been quintupling
you must not have been quintupling
they must not have been quintupling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I quintuple?
must you quintuple?
must he quintuple?
must we quintuple?
must you quintuple?
must they quintuple? 	must I be quintupling?
must you be quintupling?
must he be quintupling?
must we be quintupling?
must you be quintupling?
must they be quintupling? 	must I have quintupled?
must you have quintupled?
must he have quintupled?
must we have quintupled?
must you have quintupled?
must they have quintupled? 	must I have been quintupling?
must you have been quintupling?
must he have been quintupling?
must we have been quintupling?
must you have been quintupling?
must they have been quintupling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not quintuple?
must you not quintuple?
must he not quintuple?
must we not quintuple?
must you not quintuple?
must they not quintuple? 	must I not be quintupling?
must you not be quintupling?
must he not be quintupling?
must we not be quintupling?
must you not be quintupling?
must they not be quintupling? 	must I not have quintupled?
must you not have quintupled?
must he not have quintupled?
must we not have quintupled?
must you not have quintupled?
must they not have quintupled? 	must I not have been quintupling?
must you not have been quintupling?
must he not have been quintupling?
must we not have been quintupling?
must you not have been quintupling?
must they not have been quintupling?