must retard
Regular verb: retard - retarded- retarded

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must retard
you must retard
she must retard
we must retard
you must retard
they must retard 	I must be retarding
you must be retarding
she must be retarding
we must be retarding
you must be retarding
they must be retarding	I must have retarded
you must have retarded
she must have retarded
we must have retarded
you must have retarded
they must have retarded	I must have been retarding
you must have been retarding
she must have been retarding
we must have been retarding
you must have been retarding
they must have been retarding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't retard
you mustn't retard
she mustn't retard
we mustn't retard
you mustn't retard
they mustn't retard 	I mustn't be retarding
you mustn't be retarding
she mustn't be retarding
we mustn't be retarding
you mustn't be retarding
they mustn't be retarding	I mustn't have retarded
you mustn't have retarded
she mustn't have retarded
we mustn't have retarded
you mustn't have retarded
they mustn't have retarded	I mustn't have been retarding
you mustn't have been retarding
she mustn't have been retarding
we mustn't have been retarding
you mustn't have been retarding
they mustn't have been retarding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I retard?
must you retard?
must she retard?
must we retard?
must you retard?
must they retard? 	must I be retarding?
must you be retarding?
must she be retarding?
must we be retarding?
must you be retarding?
must they be retarding? 	must I have retarded?
must you have retarded?
must she have retarded?
must we have retarded?
must you have retarded?
must they have retarded? 	must I have been retarding?
must you have been retarding?
must she have been retarding?
must we have been retarding?
must you have been retarding?
must they have been retarding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I retard?
mustn't you retard?
mustn't she retard?
mustn't we retard?
mustn't you retard?
mustn't they retard? 	mustn't I be retarding?
mustn't you be retarding?
mustn't she be retarding?
mustn't we be retarding?
mustn't you be retarding?
mustn't they be retarding? 	mustn't I have retarded?
mustn't you have retarded?
mustn't she have retarded?
mustn't we have retarded?
mustn't you have retarded?
mustn't they have retarded? 	mustn't I have been retarding?
mustn't you have been retarding?
mustn't she have been retarding?
mustn't we have been retarding?
mustn't you have been retarding?
mustn't they have been retarding?