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