must oblige
Regular verb: oblige - obliged- obliged

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must oblige
you must oblige
he must oblige
we must oblige
you must oblige
they must oblige 	I must be obliging
you must be obliging
he must be obliging
we must be obliging
you must be obliging
they must be obliging	I must have obliged
you must have obliged
he must have obliged
we must have obliged
you must have obliged
they must have obliged	I must have been obliging
you must have been obliging
he must have been obliging
we must have been obliging
you must have been obliging
they must have been obliging	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't oblige
you mustn't oblige
he mustn't oblige
we mustn't oblige
you mustn't oblige
they mustn't oblige 	I mustn't be obliging
you mustn't be obliging
he mustn't be obliging
we mustn't be obliging
you mustn't be obliging
they mustn't be obliging	I mustn't have obliged
you mustn't have obliged
he mustn't have obliged
we mustn't have obliged
you mustn't have obliged
they mustn't have obliged	I mustn't have been obliging
you mustn't have been obliging
he mustn't have been obliging
we mustn't have been obliging
you mustn't have been obliging
they mustn't have been obliging	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I oblige?
must you oblige?
must he oblige?
must we oblige?
must you oblige?
must they oblige? 	must I be obliging?
must you be obliging?
must he be obliging?
must we be obliging?
must you be obliging?
must they be obliging? 	must I have obliged?
must you have obliged?
must he have obliged?
must we have obliged?
must you have obliged?
must they have obliged? 	must I have been obliging?
must you have been obliging?
must he have been obliging?
must we have been obliging?
must you have been obliging?
must they have been obliging? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I oblige?
mustn't you oblige?
mustn't he oblige?
mustn't we oblige?
mustn't you oblige?
mustn't they oblige? 	mustn't I be obliging?
mustn't you be obliging?
mustn't he be obliging?
mustn't we be obliging?
mustn't you be obliging?
mustn't they be obliging? 	mustn't I have obliged?
mustn't you have obliged?
mustn't he have obliged?
mustn't we have obliged?
mustn't you have obliged?
mustn't they have obliged? 	mustn't I have been obliging?
mustn't you have been obliging?
mustn't he have been obliging?
mustn't we have been obliging?
mustn't you have been obliging?
mustn't they have been obliging?