I must sign you must sign she must sign we must sign you must sign they must sign
Forma con V-ing
I must be signing you must be signing she must be signing we must be signing you must be signing they must be signing
Perfecto
I must have signed you must have signed she must have signed we must have signed you must have signed they must have signed
Perfecto con V-ing
I must have been signing you must have been signing she must have been signing we must have been signing you must have been signing they must have been signing
Negación
Forma simple
I mustn't sign you mustn't sign she mustn't sign we mustn't sign you mustn't sign they mustn't sign
Forma con V-ing
I mustn't be signing you mustn't be signing she mustn't be signing we mustn't be signing you mustn't be signing they mustn't be signing
Perfecto
I mustn't have signed you mustn't have signed she mustn't have signed we mustn't have signed you mustn't have signed they mustn't have signed
Perfecto con V-ing
I mustn't have been signing you mustn't have been signing she mustn't have been signing we mustn't have been signing you mustn't have been signing they mustn't have been signing
Forma interrogativa
Forma simple
must I sign? must you sign? must she sign? must we sign? must you sign? must they sign?
Forma con V-ing
must I be signing? must you be signing? must she be signing? must we be signing? must you be signing? must they be signing?
Perfecto
must I have signed? must you have signed? must she have signed? must we have signed? must you have signed? must they have signed?
Perfecto con V-ing
must I have been signing? must you have been signing? must she have been signing? must we have been signing? must you have been signing? must they have been signing?
Forma interro-negativa
Forma simple
mustn't I sign? mustn't you sign? mustn't she sign? mustn't we sign? mustn't you sign? mustn't they sign?
Forma con V-ing
mustn't I be signing? mustn't you be signing? mustn't she be signing? mustn't we be signing? mustn't you be signing? mustn't they be signing?
Perfecto
mustn't I have signed? mustn't you have signed? mustn't she have signed? mustn't we have signed? mustn't you have signed? mustn't they have signed?
Perfecto con V-ing
mustn't I have been signing? mustn't you have been signing? mustn't she have been signing? mustn't we have been signing? mustn't you have been signing? mustn't they have been signing?