must understand
Verbe irrégulier : understand - understood- understood
Traduction française : comprendre 

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must understand
you must understand
she must understand
we must understand
you must understand
they must understand 	I must be understanding
you must be understanding
she must be understanding
we must be understanding
you must be understanding
they must be understanding	I must have understood
you must have understood
she must have understood
we must have understood
you must have understood
they must have understood	I must have been understanding
you must have been understanding
she must have been understanding
we must have been understanding
you must have been understanding
they must have been understanding	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must not understand
you must not understand
she must not understand
we must not understand
you must not understand
they must not understand 	I must not be understanding
you must not be understanding
she must not be understanding
we must not be understanding
you must not be understanding
they must not be understanding	I must not have understood
you must not have understood
she must not have understood
we must not have understood
you must not have understood
they must not have understood	I must not have been understanding
you must not have been understanding
she must not have been understanding
we must not have been understanding
you must not have been understanding
they must not have been understanding	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I understand?
must you understand?
must she understand?
must we understand?
must you understand?
must they understand? 	must I be understanding?
must you be understanding?
must she be understanding?
must we be understanding?
must you be understanding?
must they be understanding? 	must I have understood?
must you have understood?
must she have understood?
must we have understood?
must you have understood?
must they have understood? 	must I have been understanding?
must you have been understanding?
must she have been understanding?
must we have been understanding?
must you have been understanding?
must they have been understanding? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I not understand?
must you not understand?
must she not understand?
must we not understand?
must you not understand?
must they not understand? 	must I not be understanding?
must you not be understanding?
must she not be understanding?
must we not be understanding?
must you not be understanding?
must they not be understanding? 	must I not have understood?
must you not have understood?
must she not have understood?
must we not have understood?
must you not have understood?
must they not have understood? 	must I not have been understanding?
must you not have been understanding?
must she not have been understanding?
must we not have been understanding?
must you not have been understanding?
must they not have been understanding?