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