must pertain
Regular verb: pertain - pertained- pertained

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must pertain
you must pertain
he must pertain
we must pertain
you must pertain
they must pertain 	I must be pertaining
you must be pertaining
he must be pertaining
we must be pertaining
you must be pertaining
they must be pertaining	I must have pertained
you must have pertained
he 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
he 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
he 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
he 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
he 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
he 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 he pertain?
must we pertain?
must you pertain?
must they pertain? 	must I be pertaining?
must you be pertaining?
must he be pertaining?
must we be pertaining?
must you be pertaining?
must they be pertaining? 	must I have pertained?
must you have pertained?
must he 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 he 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 he 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 he 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 he 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 he have been pertaining?
mustn't we have been pertaining?
mustn't you have been pertaining?
mustn't they have been pertaining?