must understand
Verbo irregolare: understand - understood- understood

Affermazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con 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	

Negazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I mustn't understand
you mustn't understand
she mustn't understand
we mustn't understand
you mustn't understand
they mustn't understand 	I mustn't be understanding
you mustn't be understanding
she mustn't be understanding
we mustn't be understanding
you mustn't be understanding
they mustn't be understanding	I mustn't have understood
you mustn't have understood
she mustn't have understood
we mustn't have understood
you mustn't have understood
they mustn't have understood	I mustn't have been understanding
you mustn't have been understanding
she mustn't have been understanding
we mustn't have been understanding
you mustn't have been understanding
they mustn't have been understanding	

Forma interrogativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con 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? 	

Forma interro-negativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
mustn't I understand?
mustn't you understand?
mustn't she understand?
mustn't we understand?
mustn't you understand?
mustn't they understand? 	mustn't I be understanding?
mustn't you be understanding?
mustn't she be understanding?
mustn't we be understanding?
mustn't you be understanding?
mustn't they be understanding? 	mustn't I have understood?
mustn't you have understood?
mustn't she have understood?
mustn't we have understood?
mustn't you have understood?
mustn't they have understood? 	mustn't I have been understanding?
mustn't you have been understanding?
mustn't she have been understanding?
mustn't we have been understanding?
mustn't you have been understanding?
mustn't they have been understanding?