must alter
Verbo regular: alter - altered- altered

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must alter
you must alter
she must alter
we must alter
you must alter
they must alter 	I must be altering
you must be altering
she must be altering
we must be altering
you must be altering
they must be altering	I must have altered
you must have altered
she must have altered
we must have altered
you must have altered
they must have altered	I must have been altering
you must have been altering
she must have been altering
we must have been altering
you must have been altering
they must have been altering	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't alter
you mustn't alter
she mustn't alter
we mustn't alter
you mustn't alter
they mustn't alter 	I mustn't be altering
you mustn't be altering
she mustn't be altering
we mustn't be altering
you mustn't be altering
they mustn't be altering	I mustn't have altered
you mustn't have altered
she mustn't have altered
we mustn't have altered
you mustn't have altered
they mustn't have altered	I mustn't have been altering
you mustn't have been altering
she mustn't have been altering
we mustn't have been altering
you mustn't have been altering
they mustn't have been altering	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I alter?
must you alter?
must she alter?
must we alter?
must you alter?
must they alter? 	must I be altering?
must you be altering?
must she be altering?
must we be altering?
must you be altering?
must they be altering? 	must I have altered?
must you have altered?
must she have altered?
must we have altered?
must you have altered?
must they have altered? 	must I have been altering?
must you have been altering?
must she have been altering?
must we have been altering?
must you have been altering?
must they have been altering? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I alter?
mustn't you alter?
mustn't she alter?
mustn't we alter?
mustn't you alter?
mustn't they alter? 	mustn't I be altering?
mustn't you be altering?
mustn't she be altering?
mustn't we be altering?
mustn't you be altering?
mustn't they be altering? 	mustn't I have altered?
mustn't you have altered?
mustn't she have altered?
mustn't we have altered?
mustn't you have altered?
mustn't they have altered? 	mustn't I have been altering?
mustn't you have been altering?
mustn't she have been altering?
mustn't we have been altering?
mustn't you have been altering?
mustn't they have been altering?