I must refer you must refer he must refer we must refer you must refer they must refer
Forma con V-ing
I must be referring you must be referring he must be referring we must be referring you must be referring they must be referring
Perfecto
I must have referred you must have referred he must have referred we must have referred you must have referred they must have referred
Perfecto con V-ing
I must have been referring you must have been referring he must have been referring we must have been referring you must have been referring they must have been referring
Negación
Forma simple
I mustn't refer you mustn't refer he mustn't refer we mustn't refer you mustn't refer they mustn't refer
Forma con V-ing
I mustn't be referring you mustn't be referring he mustn't be referring we mustn't be referring you mustn't be referring they mustn't be referring
Perfecto
I mustn't have referred you mustn't have referred he mustn't have referred we mustn't have referred you mustn't have referred they mustn't have referred
Perfecto con V-ing
I mustn't have been referring you mustn't have been referring he mustn't have been referring we mustn't have been referring you mustn't have been referring they mustn't have been referring
Forma interrogativa
Forma simple
must I refer? must you refer? must he refer? must we refer? must you refer? must they refer?
Forma con V-ing
must I be referring? must you be referring? must he be referring? must we be referring? must you be referring? must they be referring?
Perfecto
must I have referred? must you have referred? must he have referred? must we have referred? must you have referred? must they have referred?
Perfecto con V-ing
must I have been referring? must you have been referring? must he have been referring? must we have been referring? must you have been referring? must they have been referring?
Forma interro-negativa
Forma simple
mustn't I refer? mustn't you refer? mustn't he refer? mustn't we refer? mustn't you refer? mustn't they refer?
Forma con V-ing
mustn't I be referring? mustn't you be referring? mustn't he be referring? mustn't we be referring? mustn't you be referring? mustn't they be referring?
Perfecto
mustn't I have referred? mustn't you have referred? mustn't he have referred? mustn't we have referred? mustn't you have referred? mustn't they have referred?
Perfecto con V-ing
mustn't I have been referring? mustn't you have been referring? mustn't he have been referring? mustn't we have been referring? mustn't you have been referring? mustn't they have been referring?