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 must not serve you must not serve he must not serve we must not serve you must not serve they must not serve
Forma con V-ing
I must not be serving you must not be serving he must not be serving we must not be serving you must not be serving they must not be serving
Perfecto
I must not have served you must not have served he must not have served we must not have served you must not have served they must not have served
Perfecto con V-ing
I must not have been serving you must not have been serving he must not have been serving we must not have been serving you must not have been serving they must not 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
must I not serve? must you not serve? must he not serve? must we not serve? must you not serve? must they not serve?
Forma con V-ing
must I not be serving? must you not be serving? must he not be serving? must we not be serving? must you not be serving? must they not be serving?
Perfecto
must I not have served? must you not have served? must he not have served? must we not have served? must you not have served? must they not have served?
Perfecto con V-ing
must I not have been serving? must you not have been serving? must he not have been serving? must we not have been serving? must you not have been serving? must they not have been serving?