must characterize
Regular verb: characterize - characterized- characterized

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must characterize
you must characterize
he must characterize
we must characterize
you must characterize
they must characterize 	I must be characterizing
you must be characterizing
he must be characterizing
we must be characterizing
you must be characterizing
they must be characterizing	I must have characterized
you must have characterized
he must have characterized
we must have characterized
you must have characterized
they must have characterized	I must have been characterizing
you must have been characterizing
he must have been characterizing
we must have been characterizing
you must have been characterizing
they must have been characterizing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not characterize
you must not characterize
he must not characterize
we must not characterize
you must not characterize
they must not characterize 	I must not be characterizing
you must not be characterizing
he must not be characterizing
we must not be characterizing
you must not be characterizing
they must not be characterizing	I must not have characterized
you must not have characterized
he must not have characterized
we must not have characterized
you must not have characterized
they must not have characterized	I must not have been characterizing
you must not have been characterizing
he must not have been characterizing
we must not have been characterizing
you must not have been characterizing
they must not have been characterizing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I characterize?
must you characterize?
must he characterize?
must we characterize?
must you characterize?
must they characterize? 	must I be characterizing?
must you be characterizing?
must he be characterizing?
must we be characterizing?
must you be characterizing?
must they be characterizing? 	must I have characterized?
must you have characterized?
must he have characterized?
must we have characterized?
must you have characterized?
must they have characterized? 	must I have been characterizing?
must you have been characterizing?
must he have been characterizing?
must we have been characterizing?
must you have been characterizing?
must they have been characterizing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not characterize?
must you not characterize?
must he not characterize?
must we not characterize?
must you not characterize?
must they not characterize? 	must I not be characterizing?
must you not be characterizing?
must he not be characterizing?
must we not be characterizing?
must you not be characterizing?
must they not be characterizing? 	must I not have characterized?
must you not have characterized?
must he not have characterized?
must we not have characterized?
must you not have characterized?
must they not have characterized? 	must I not have been characterizing?
must you not have been characterizing?
must he not have been characterizing?
must we not have been characterizing?
must you not have been characterizing?
must they not have been characterizing?