must undertake
Verbo irregular: undertake - undertook- undertaken

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must undertake
you must undertake
he must undertake
we must undertake
you must undertake
they must undertake 	I must be undertaking
you must be undertaking
he must be undertaking
we must be undertaking
you must be undertaking
they must be undertaking	I must have undertaken
you must have undertaken
he must have undertaken
we must have undertaken
you must have undertaken
they must have undertaken	I must have been undertaking
you must have been undertaking
he must have been undertaking
we must have been undertaking
you must have been undertaking
they must have been undertaking	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I mustn't undertake
you mustn't undertake
he mustn't undertake
we mustn't undertake
you mustn't undertake
they mustn't undertake 	I mustn't be undertaking
you mustn't be undertaking
he mustn't be undertaking
we mustn't be undertaking
you mustn't be undertaking
they mustn't be undertaking	I mustn't have undertaken
you mustn't have undertaken
he mustn't have undertaken
we mustn't have undertaken
you mustn't have undertaken
they mustn't have undertaken	I mustn't have been undertaking
you mustn't have been undertaking
he mustn't have been undertaking
we mustn't have been undertaking
you mustn't have been undertaking
they mustn't have been undertaking	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I undertake?
must you undertake?
must he undertake?
must we undertake?
must you undertake?
must they undertake? 	must I be undertaking?
must you be undertaking?
must he be undertaking?
must we be undertaking?
must you be undertaking?
must they be undertaking? 	must I have undertaken?
must you have undertaken?
must he have undertaken?
must we have undertaken?
must you have undertaken?
must they have undertaken? 	must I have been undertaking?
must you have been undertaking?
must he have been undertaking?
must we have been undertaking?
must you have been undertaking?
must they have been undertaking? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
mustn't I undertake?
mustn't you undertake?
mustn't he undertake?
mustn't we undertake?
mustn't you undertake?
mustn't they undertake? 	mustn't I be undertaking?
mustn't you be undertaking?
mustn't he be undertaking?
mustn't we be undertaking?
mustn't you be undertaking?
mustn't they be undertaking? 	mustn't I have undertaken?
mustn't you have undertaken?
mustn't he have undertaken?
mustn't we have undertaken?
mustn't you have undertaken?
mustn't they have undertaken? 	mustn't I have been undertaking?
mustn't you have been undertaking?
mustn't he have been undertaking?
mustn't we have been undertaking?
mustn't you have been undertaking?
mustn't they have been undertaking?