I must found you must found he must found we must found you must found they must found
Forma con V-ing
I must be founding you must be founding he must be founding we must be founding you must be founding they must be founding
Perfecto
I must have founded you must have founded he must have founded we must have founded you must have founded they must have founded
Perfecto con V-ing
I must have been founding you must have been founding he must have been founding we must have been founding you must have been founding they must have been founding
Negación
Forma simple
I must not found you must not found he must not found we must not found you must not found they must not found
Forma con V-ing
I must not be founding you must not be founding he must not be founding we must not be founding you must not be founding they must not be founding
Perfecto
I must not have founded you must not have founded he must not have founded we must not have founded you must not have founded they must not have founded
Perfecto con V-ing
I must not have been founding you must not have been founding he must not have been founding we must not have been founding you must not have been founding they must not have been founding
Forma interrogativa
Forma simple
must I found? must you found? must he found? must we found? must you found? must they found?
Forma con V-ing
must I be founding? must you be founding? must he be founding? must we be founding? must you be founding? must they be founding?
Perfecto
must I have founded? must you have founded? must he have founded? must we have founded? must you have founded? must they have founded?
Perfecto con V-ing
must I have been founding? must you have been founding? must he have been founding? must we have been founding? must you have been founding? must they have been founding?
Forma interro-negativa
Forma simple
must I not found? must you not found? must he not found? must we not found? must you not found? must they not found?
Forma con V-ing
must I not be founding? must you not be founding? must he not be founding? must we not be founding? must you not be founding? must they not be founding?
Perfecto
must I not have founded? must you not have founded? must he not have founded? must we not have founded? must you not have founded? must they not have founded?
Perfecto con V-ing
must I not have been founding? must you not have been founding? must he not have been founding? must we not have been founding? must you not have been founding? must they not have been founding?