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