I must retard you must retard she must retard we must retard you must retard they must retard
Forma con V-ing
I must be retarding you must be retarding she must be retarding we must be retarding you must be retarding they must be retarding
Perfecto
I must have retarded you must have retarded she must have retarded we must have retarded you must have retarded they must have retarded
Perfecto con V-ing
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
Negación
Forma simple
I must not retard you must not retard she must not retard we must not retard you must not retard they must not retard
Forma con V-ing
I must not be retarding you must not be retarding she must not be retarding we must not be retarding you must not be retarding they must not be retarding
Perfecto
I must not have retarded you must not have retarded she must not have retarded we must not have retarded you must not have retarded they must not have retarded
Perfecto con V-ing
I must not have been retarding you must not have been retarding she 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
must I retard? must you retard? must she retard? must we retard? must you retard? must they retard?
Forma con V-ing
must I be retarding? must you be retarding? must she be retarding? must we be retarding? must you be retarding? must they be retarding?
Perfecto
must I have retarded? must you have retarded? must she have retarded? must we have retarded? must you have retarded? must they have retarded?
Perfecto con V-ing
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?
Forma interro-negativa
Forma simple
must I not retard? must you not retard? must she not retard? must we not retard? must you not retard? must they not retard?
Forma con V-ing
must I not be retarding? must you not be retarding? must she not be retarding? must we not be retarding? must you not be retarding? must they not be retarding?
Perfecto
must I not have retarded? must you not have retarded? must she not have retarded? must we not have retarded? must you not have retarded? must they not have retarded?
Perfecto con V-ing
must I not have been retarding? must you not have been retarding? must she not have been retarding? must we not have been retarding? must you not have been retarding? must they not have been retarding?