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