must biff
Verbe régulier : biff - biffed- biffed
Traduction française : flanquer un coup de poing à 

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must biff
you must biff
she must biff
we must biff
you must biff
they must biff 	I must be biffing
you must be biffing
she must be biffing
we must be biffing
you must be biffing
they must be biffing	I must have biffed
you must have biffed
she must have biffed
we must have biffed
you must have biffed
they must have biffed	I must have been biffing
you must have been biffing
she must have been biffing
we must have been biffing
you must have been biffing
they must have been biffing	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't biff
you mustn't biff
she mustn't biff
we mustn't biff
you mustn't biff
they mustn't biff 	I mustn't be biffing
you mustn't be biffing
she mustn't be biffing
we mustn't be biffing
you mustn't be biffing
they mustn't be biffing	I mustn't have biffed
you mustn't have biffed
she mustn't have biffed
we mustn't have biffed
you mustn't have biffed
they mustn't have biffed	I mustn't have been biffing
you mustn't have been biffing
she mustn't have been biffing
we mustn't have been biffing
you mustn't have been biffing
they mustn't have been biffing	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I biff?
must you biff?
must she biff?
must we biff?
must you biff?
must they biff? 	must I be biffing?
must you be biffing?
must she be biffing?
must we be biffing?
must you be biffing?
must they be biffing? 	must I have biffed?
must you have biffed?
must she have biffed?
must we have biffed?
must you have biffed?
must they have biffed? 	must I have been biffing?
must you have been biffing?
must she have been biffing?
must we have been biffing?
must you have been biffing?
must they have been biffing? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I biff?
mustn't you biff?
mustn't she biff?
mustn't we biff?
mustn't you biff?
mustn't they biff? 	mustn't I be biffing?
mustn't you be biffing?
mustn't she be biffing?
mustn't we be biffing?
mustn't you be biffing?
mustn't they be biffing? 	mustn't I have biffed?
mustn't you have biffed?
mustn't she have biffed?
mustn't we have biffed?
mustn't you have biffed?
mustn't they have biffed? 	mustn't I have been biffing?
mustn't you have been biffing?
mustn't she have been biffing?
mustn't we have been biffing?
mustn't you have been biffing?
mustn't they have been biffing?