must retard
Verbo regular: retard - retarded- retarded

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must retard
you must retard
he must retard
we must retard
you must retard
they must retard 	I must be retarding
you must be retarding
he must be retarding
we must be retarding
you must be retarding
they must be retarding	I must have retarded
you must have retarded
he 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
he must have been retarding
we must have been retarding
you must have been retarding
they must have been retarding	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must not retard
you must not retard
he must not retard
we must not retard
you must not retard
they must not retard 	I must not be retarding
you must not be retarding
he must not be retarding
we must not be retarding
you must not be retarding
they must not be retarding	I must not have retarded
you must not have retarded
he must not have retarded
we must not have retarded
you must not have retarded
they must not have retarded	I must not have been retarding
you must not have been retarding
he must not have been retarding
we must not have been retarding
you must not have been retarding
they must not have been retarding	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I retard?
must you retard?
must he retard?
must we retard?
must you retard?
must they retard? 	must I be retarding?
must you be retarding?
must he be retarding?
must we be retarding?
must you be retarding?
must they be retarding? 	must I have retarded?
must you have retarded?
must he 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 he have been retarding?
must we have been retarding?
must you have been retarding?
must they have been retarding? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I not retard?
must you not retard?
must he not retard?
must we not retard?
must you not retard?
must they not retard? 	must I not be retarding?
must you not be retarding?
must he not be retarding?
must we not be retarding?
must you not be retarding?
must they not be retarding? 	must I not have retarded?
must you not have retarded?
must he not have retarded?
must we not have retarded?
must you not have retarded?
must they not have retarded? 	must I not have been retarding?
must you not have been retarding?
must he not have been retarding?
must we not have been retarding?
must you not have been retarding?
must they not have been retarding?