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