must retroact
Verbe régulier : retroact - retroacted- retroacted

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must retroact
you must retroact
he must retroact
we must retroact
you must retroact
they must retroact 	I must be retroacting
you must be retroacting
he must be retroacting
we must be retroacting
you must be retroacting
they must be retroacting	I must have retroacted
you must have retroacted
he must have retroacted
we must have retroacted
you must have retroacted
they must have retroacted	I must have been retroacting
you must have been retroacting
he must have been retroacting
we must have been retroacting
you must have been retroacting
they must have been retroacting	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't retroact
you mustn't retroact
he mustn't retroact
we mustn't retroact
you mustn't retroact
they mustn't retroact 	I mustn't be retroacting
you mustn't be retroacting
he mustn't be retroacting
we mustn't be retroacting
you mustn't be retroacting
they mustn't be retroacting	I mustn't have retroacted
you mustn't have retroacted
he mustn't have retroacted
we mustn't have retroacted
you mustn't have retroacted
they mustn't have retroacted	I mustn't have been retroacting
you mustn't have been retroacting
he mustn't have been retroacting
we mustn't have been retroacting
you mustn't have been retroacting
they mustn't have been retroacting	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I retroact?
must you retroact?
must he retroact?
must we retroact?
must you retroact?
must they retroact? 	must I be retroacting?
must you be retroacting?
must he be retroacting?
must we be retroacting?
must you be retroacting?
must they be retroacting? 	must I have retroacted?
must you have retroacted?
must he have retroacted?
must we have retroacted?
must you have retroacted?
must they have retroacted? 	must I have been retroacting?
must you have been retroacting?
must he have been retroacting?
must we have been retroacting?
must you have been retroacting?
must they have been retroacting? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I retroact?
mustn't you retroact?
mustn't he retroact?
mustn't we retroact?
mustn't you retroact?
mustn't they retroact? 	mustn't I be retroacting?
mustn't you be retroacting?
mustn't he be retroacting?
mustn't we be retroacting?
mustn't you be retroacting?
mustn't they be retroacting? 	mustn't I have retroacted?
mustn't you have retroacted?
mustn't he have retroacted?
mustn't we have retroacted?
mustn't you have retroacted?
mustn't they have retroacted? 	mustn't I have been retroacting?
mustn't you have been retroacting?
mustn't he have been retroacting?
mustn't we have been retroacting?
mustn't you have been retroacting?
mustn't they have been retroacting?