must rival
Regular verb: rival - rivalled- rivalled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must rival
you must rival
she must rival
we must rival
you must rival
they must rival 	I must be rivalling
you must be rivalling
she must be rivalling
we must be rivalling
you must be rivalling
they must be rivalling	I must have rivalled
you must have rivalled
she must have rivalled
we must have rivalled
you must have rivalled
they must have rivalled	I must have been rivalling
you must have been rivalling
she must have been rivalling
we must have been rivalling
you must have been rivalling
they must have been rivalling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't rival
you mustn't rival
she mustn't rival
we mustn't rival
you mustn't rival
they mustn't rival 	I mustn't be rivalling
you mustn't be rivalling
she mustn't be rivalling
we mustn't be rivalling
you mustn't be rivalling
they mustn't be rivalling	I mustn't have rivalled
you mustn't have rivalled
she mustn't have rivalled
we mustn't have rivalled
you mustn't have rivalled
they mustn't have rivalled	I mustn't have been rivalling
you mustn't have been rivalling
she mustn't have been rivalling
we mustn't have been rivalling
you mustn't have been rivalling
they mustn't have been rivalling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I rival?
must you rival?
must she rival?
must we rival?
must you rival?
must they rival? 	must I be rivalling?
must you be rivalling?
must she be rivalling?
must we be rivalling?
must you be rivalling?
must they be rivalling? 	must I have rivalled?
must you have rivalled?
must she have rivalled?
must we have rivalled?
must you have rivalled?
must they have rivalled? 	must I have been rivalling?
must you have been rivalling?
must she have been rivalling?
must we have been rivalling?
must you have been rivalling?
must they have been rivalling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I rival?
mustn't you rival?
mustn't she rival?
mustn't we rival?
mustn't you rival?
mustn't they rival? 	mustn't I be rivalling?
mustn't you be rivalling?
mustn't she be rivalling?
mustn't we be rivalling?
mustn't you be rivalling?
mustn't they be rivalling? 	mustn't I have rivalled?
mustn't you have rivalled?
mustn't she have rivalled?
mustn't we have rivalled?
mustn't you have rivalled?
mustn't they have rivalled? 	mustn't I have been rivalling?
mustn't you have been rivalling?
mustn't she have been rivalling?
mustn't we have been rivalling?
mustn't you have been rivalling?
mustn't they have been rivalling?