must undersign
Verbe régulier : undersign - undersigned- undersigned

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must undersign
you must undersign
he must undersign
we must undersign
you must undersign
they must undersign 	I must be undersigning
you must be undersigning
he must be undersigning
we must be undersigning
you must be undersigning
they must be undersigning	I must have undersigned
you must have undersigned
he must have undersigned
we must have undersigned
you must have undersigned
they must have undersigned	I must have been undersigning
you must have been undersigning
he must have been undersigning
we must have been undersigning
you must have been undersigning
they must have been undersigning	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't undersign
you mustn't undersign
he mustn't undersign
we mustn't undersign
you mustn't undersign
they mustn't undersign 	I mustn't be undersigning
you mustn't be undersigning
he mustn't be undersigning
we mustn't be undersigning
you mustn't be undersigning
they mustn't be undersigning	I mustn't have undersigned
you mustn't have undersigned
he mustn't have undersigned
we mustn't have undersigned
you mustn't have undersigned
they mustn't have undersigned	I mustn't have been undersigning
you mustn't have been undersigning
he mustn't have been undersigning
we mustn't have been undersigning
you mustn't have been undersigning
they mustn't have been undersigning	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I undersign?
must you undersign?
must he undersign?
must we undersign?
must you undersign?
must they undersign? 	must I be undersigning?
must you be undersigning?
must he be undersigning?
must we be undersigning?
must you be undersigning?
must they be undersigning? 	must I have undersigned?
must you have undersigned?
must he have undersigned?
must we have undersigned?
must you have undersigned?
must they have undersigned? 	must I have been undersigning?
must you have been undersigning?
must he have been undersigning?
must we have been undersigning?
must you have been undersigning?
must they have been undersigning? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I undersign?
mustn't you undersign?
mustn't he undersign?
mustn't we undersign?
mustn't you undersign?
mustn't they undersign? 	mustn't I be undersigning?
mustn't you be undersigning?
mustn't he be undersigning?
mustn't we be undersigning?
mustn't you be undersigning?
mustn't they be undersigning? 	mustn't I have undersigned?
mustn't you have undersigned?
mustn't he have undersigned?
mustn't we have undersigned?
mustn't you have undersigned?
mustn't they have undersigned? 	mustn't I have been undersigning?
mustn't you have been undersigning?
mustn't he have been undersigning?
mustn't we have been undersigning?
mustn't you have been undersigning?
mustn't they have been undersigning?