must pertain
Regular verb: pertain - pertained- pertained

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must pertain
you must pertain
she must pertain
we must pertain
you must pertain
they must pertain 	I must be pertaining
you must be pertaining
she must be pertaining
we must be pertaining
you must be pertaining
they must be pertaining	I must have pertained
you must have pertained
she must have pertained
we must have pertained
you must have pertained
they must have pertained	I must have been pertaining
you must have been pertaining
she must have been pertaining
we must have been pertaining
you must have been pertaining
they must have been pertaining	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't pertain
you mustn't pertain
she mustn't pertain
we mustn't pertain
you mustn't pertain
they mustn't pertain 	I mustn't be pertaining
you mustn't be pertaining
she mustn't be pertaining
we mustn't be pertaining
you mustn't be pertaining
they mustn't be pertaining	I mustn't have pertained
you mustn't have pertained
she mustn't have pertained
we mustn't have pertained
you mustn't have pertained
they mustn't have pertained	I mustn't have been pertaining
you mustn't have been pertaining
she mustn't have been pertaining
we mustn't have been pertaining
you mustn't have been pertaining
they mustn't have been pertaining	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I pertain?
must you pertain?
must she pertain?
must we pertain?
must you pertain?
must they pertain? 	must I be pertaining?
must you be pertaining?
must she be pertaining?
must we be pertaining?
must you be pertaining?
must they be pertaining? 	must I have pertained?
must you have pertained?
must she have pertained?
must we have pertained?
must you have pertained?
must they have pertained? 	must I have been pertaining?
must you have been pertaining?
must she have been pertaining?
must we have been pertaining?
must you have been pertaining?
must they have been pertaining? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I pertain?
mustn't you pertain?
mustn't she pertain?
mustn't we pertain?
mustn't you pertain?
mustn't they pertain? 	mustn't I be pertaining?
mustn't you be pertaining?
mustn't she be pertaining?
mustn't we be pertaining?
mustn't you be pertaining?
mustn't they be pertaining? 	mustn't I have pertained?
mustn't you have pertained?
mustn't she have pertained?
mustn't we have pertained?
mustn't you have pertained?
mustn't they have pertained? 	mustn't I have been pertaining?
mustn't you have been pertaining?
mustn't she have been pertaining?
mustn't we have been pertaining?
mustn't you have been pertaining?
mustn't they have been pertaining?