I must frown you must frown he must frown we must frown you must frown they must frown
Forma con V-ing
I must be frowning you must be frowning he must be frowning we must be frowning you must be frowning they must be frowning
Perfecto
I must have frowned you must have frowned he must have frowned we must have frowned you must have frowned they must have frowned
Perfecto con V-ing
I must have been frowning you must have been frowning he must have been frowning we must have been frowning you must have been frowning they must have been frowning
Negación
Forma simple
I must not frown you must not frown he must not frown we must not frown you must not frown they must not frown
Forma con V-ing
I must not be frowning you must not be frowning he must not be frowning we must not be frowning you must not be frowning they must not be frowning
Perfecto
I must not have frowned you must not have frowned he must not have frowned we must not have frowned you must not have frowned they must not have frowned
Perfecto con V-ing
I must not have been frowning you must not have been frowning he must not have been frowning we must not have been frowning you must not have been frowning they must not have been frowning
Forma interrogativa
Forma simple
must I frown? must you frown? must he frown? must we frown? must you frown? must they frown?
Forma con V-ing
must I be frowning? must you be frowning? must he be frowning? must we be frowning? must you be frowning? must they be frowning?
Perfecto
must I have frowned? must you have frowned? must he have frowned? must we have frowned? must you have frowned? must they have frowned?
Perfecto con V-ing
must I have been frowning? must you have been frowning? must he have been frowning? must we have been frowning? must you have been frowning? must they have been frowning?
Forma interro-negativa
Forma simple
must I not frown? must you not frown? must he not frown? must we not frown? must you not frown? must they not frown?
Forma con V-ing
must I not be frowning? must you not be frowning? must he not be frowning? must we not be frowning? must you not be frowning? must they not be frowning?
Perfecto
must I not have frowned? must you not have frowned? must he not have frowned? must we not have frowned? must you not have frowned? must they not have frowned?
Perfecto con V-ing
must I not have been frowning? must you not have been frowning? must he not have been frowning? must we not have been frowning? must you not have been frowning? must they not have been frowning?