I must err you must err he must err we must err you must err they must err
Forma com 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
Perfeito
I must have erred you must have erred he must have erred we must have erred you must have erred they must have erred
Perfeito com 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
Negação
Forma simple
I must not err you must not err he must not err we must not err you must not err they must not err
Forma com V-ing
I must not be erring you must not be erring he must not be erring we must not be erring you must not be erring they must not be erring
Perfeito
I must not have erred you must not have erred he must not have erred we must not have erred you must not have erred they must not have erred
Perfeito com V-ing
I must not have been erring you must not have been erring he must not have been erring we must not have been erring you must not have been erring they must not 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 com 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?
Perfeito
must I have erred? must you have erred? must he have erred? must we have erred? must you have erred? must they have erred?
Perfeito com 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-Negação
Forma simple
must I not err? must you not err? must he not err? must we not err? must you not err? must they not err?
Forma com V-ing
must I not be erring? must you not be erring? must he not be erring? must we not be erring? must you not be erring? must they not be erring?
Perfeito
must I not have erred? must you not have erred? must he not have erred? must we not have erred? must you not have erred? must they not have erred?
Perfeito com V-ing
must I not have been erring? must you not have been erring? must he not have been erring? must we not have been erring? must you not have been erring? must they not have been erring?