must lifeguard
Verbe régulier : lifeguard - lifeguarded- lifeguarded

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must lifeguard
you must lifeguard
he must lifeguard
we must lifeguard
you must lifeguard
they must lifeguard 	I must be lifeguarding
you must be lifeguarding
he must be lifeguarding
we must be lifeguarding
you must be lifeguarding
they must be lifeguarding	I must have lifeguarded
you must have lifeguarded
he must have lifeguarded
we must have lifeguarded
you must have lifeguarded
they must have lifeguarded	I must have been lifeguarding
you must have been lifeguarding
he must have been lifeguarding
we must have been lifeguarding
you must have been lifeguarding
they must have been lifeguarding	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't lifeguard
you mustn't lifeguard
he mustn't lifeguard
we mustn't lifeguard
you mustn't lifeguard
they mustn't lifeguard 	I mustn't be lifeguarding
you mustn't be lifeguarding
he mustn't be lifeguarding
we mustn't be lifeguarding
you mustn't be lifeguarding
they mustn't be lifeguarding	I mustn't have lifeguarded
you mustn't have lifeguarded
he mustn't have lifeguarded
we mustn't have lifeguarded
you mustn't have lifeguarded
they mustn't have lifeguarded	I mustn't have been lifeguarding
you mustn't have been lifeguarding
he mustn't have been lifeguarding
we mustn't have been lifeguarding
you mustn't have been lifeguarding
they mustn't have been lifeguarding	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I lifeguard?
must you lifeguard?
must he lifeguard?
must we lifeguard?
must you lifeguard?
must they lifeguard? 	must I be lifeguarding?
must you be lifeguarding?
must he be lifeguarding?
must we be lifeguarding?
must you be lifeguarding?
must they be lifeguarding? 	must I have lifeguarded?
must you have lifeguarded?
must he have lifeguarded?
must we have lifeguarded?
must you have lifeguarded?
must they have lifeguarded? 	must I have been lifeguarding?
must you have been lifeguarding?
must he have been lifeguarding?
must we have been lifeguarding?
must you have been lifeguarding?
must they have been lifeguarding? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I lifeguard?
mustn't you lifeguard?
mustn't he lifeguard?
mustn't we lifeguard?
mustn't you lifeguard?
mustn't they lifeguard? 	mustn't I be lifeguarding?
mustn't you be lifeguarding?
mustn't he be lifeguarding?
mustn't we be lifeguarding?
mustn't you be lifeguarding?
mustn't they be lifeguarding? 	mustn't I have lifeguarded?
mustn't you have lifeguarded?
mustn't he have lifeguarded?
mustn't we have lifeguarded?
mustn't you have lifeguarded?
mustn't they have lifeguarded? 	mustn't I have been lifeguarding?
mustn't you have been lifeguarding?
mustn't he have been lifeguarding?
mustn't we have been lifeguarding?
mustn't you have been lifeguarding?
mustn't they have been lifeguarding?