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