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