must undertake
Verbe irrégulier : undertake - undertook- undertaken
Traduction française : entreprendre - s'engager à 

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must undertake
you must undertake
she must undertake
we must undertake
you must undertake
they must undertake 	I must be undertaking
you must be undertaking
she must be undertaking
we must be undertaking
you must be undertaking
they must be undertaking	I must have undertaken
you must have undertaken
she 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
she must have been undertaking
we must have been undertaking
you must have been undertaking
they must have been undertaking	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't undertake
you mustn't undertake
she 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
she 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
she 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
she mustn't have been undertaking
we mustn't have been undertaking
you mustn't have been undertaking
they mustn't have been undertaking	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I undertake?
must you undertake?
must she undertake?
must we undertake?
must you undertake?
must they undertake? 	must I be undertaking?
must you be undertaking?
must she be undertaking?
must we be undertaking?
must you be undertaking?
must they be undertaking? 	must I have undertaken?
must you have undertaken?
must she 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 she have been undertaking?
must we have been undertaking?
must you have been undertaking?
must they have been undertaking? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I undertake?
mustn't you undertake?
mustn't she 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 she 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 she 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 she have been undertaking?
mustn't we have been undertaking?
mustn't you have been undertaking?
mustn't they have been undertaking?