must modify
Verbo regular: modify - modified- modified

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must modify
you must modify
she must modify
we must modify
you must modify
they must modify 	I must be modifying
you must be modifying
she must be modifying
we must be modifying
you must be modifying
they must be modifying	I must have modified
you must have modified
she must have modified
we must have modified
you must have modified
they must have modified	I must have been modifying
you must have been modifying
she must have been modifying
we must have been modifying
you must have been modifying
they must have been modifying	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't modify
you mustn't modify
she mustn't modify
we mustn't modify
you mustn't modify
they mustn't modify 	I mustn't be modifying
you mustn't be modifying
she mustn't be modifying
we mustn't be modifying
you mustn't be modifying
they mustn't be modifying	I mustn't have modified
you mustn't have modified
she mustn't have modified
we mustn't have modified
you mustn't have modified
they mustn't have modified	I mustn't have been modifying
you mustn't have been modifying
she mustn't have been modifying
we mustn't have been modifying
you mustn't have been modifying
they mustn't have been modifying	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I modify?
must you modify?
must she modify?
must we modify?
must you modify?
must they modify? 	must I be modifying?
must you be modifying?
must she be modifying?
must we be modifying?
must you be modifying?
must they be modifying? 	must I have modified?
must you have modified?
must she have modified?
must we have modified?
must you have modified?
must they have modified? 	must I have been modifying?
must you have been modifying?
must she have been modifying?
must we have been modifying?
must you have been modifying?
must they have been modifying? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I modify?
mustn't you modify?
mustn't she modify?
mustn't we modify?
mustn't you modify?
mustn't they modify? 	mustn't I be modifying?
mustn't you be modifying?
mustn't she be modifying?
mustn't we be modifying?
mustn't you be modifying?
mustn't they be modifying? 	mustn't I have modified?
mustn't you have modified?
mustn't she have modified?
mustn't we have modified?
mustn't you have modified?
mustn't they have modified? 	mustn't I have been modifying?
mustn't you have been modifying?
mustn't she have been modifying?
mustn't we have been modifying?
mustn't you have been modifying?
mustn't they have been modifying?