must ref
Regular verb: ref - refed- refed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must ref
you must ref
she must ref
we must ref
you must ref
they must ref 	I must be refing
you must be refing
she must be refing
we must be refing
you must be refing
they must be refing	I must have refed
you must have refed
she must have refed
we must have refed
you must have refed
they must have refed	I must have been refing
you must have been refing
she must have been refing
we must have been refing
you must have been refing
they must have been refing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not ref
you must not ref
she must not ref
we must not ref
you must not ref
they must not ref 	I must not be refing
you must not be refing
she must not be refing
we must not be refing
you must not be refing
they must not be refing	I must not have refed
you must not have refed
she must not have refed
we must not have refed
you must not have refed
they must not have refed	I must not have been refing
you must not have been refing
she must not have been refing
we must not have been refing
you must not have been refing
they must not have been refing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I ref?
must you ref?
must she ref?
must we ref?
must you ref?
must they ref? 	must I be refing?
must you be refing?
must she be refing?
must we be refing?
must you be refing?
must they be refing? 	must I have refed?
must you have refed?
must she have refed?
must we have refed?
must you have refed?
must they have refed? 	must I have been refing?
must you have been refing?
must she have been refing?
must we have been refing?
must you have been refing?
must they have been refing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not ref?
must you not ref?
must she not ref?
must we not ref?
must you not ref?
must they not ref? 	must I not be refing?
must you not be refing?
must she not be refing?
must we not be refing?
must you not be refing?
must they not be refing? 	must I not have refed?
must you not have refed?
must she not have refed?
must we not have refed?
must you not have refed?
must they not have refed? 	must I not have been refing?
must you not have been refing?
must she not have been refing?
must we not have been refing?
must you not have been refing?
must they not have been refing?