must err
Verbe régulier : err - erred- erred
Traduction française : se tromper - pécher 

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must err
you must err
he must err
we must err
you must err
they must err 	I must be erring
you must be erring
he must be erring
we must be erring
you must be erring
they must be erring	I must have erred
you must have erred
he must have erred
we must have erred
you must have erred
they must have erred	I must have been erring
you must have been erring
he must have been erring
we must have been erring
you must have been erring
they must have been erring	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must not err
you must not err
he must not err
we must not err
you must not err
they must not err 	I must not be erring
you must not be erring
he must not be erring
we must not be erring
you must not be erring
they must not be erring	I must not have erred
you must not have erred
he must not have erred
we must not have erred
you must not have erred
they must not have erred	I must not have been erring
you must not have been erring
he must not have been erring
we must not have been erring
you must not have been erring
they must not have been erring	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I err?
must you err?
must he err?
must we err?
must you err?
must they err? 	must I be erring?
must you be erring?
must he be erring?
must we be erring?
must you be erring?
must they be erring? 	must I have erred?
must you have erred?
must he have erred?
must we have erred?
must you have erred?
must they have erred? 	must I have been erring?
must you have been erring?
must he have been erring?
must we have been erring?
must you have been erring?
must they have been erring? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I not err?
must you not err?
must he not err?
must we not err?
must you not err?
must they not err? 	must I not be erring?
must you not be erring?
must he not be erring?
must we not be erring?
must you not be erring?
must they not be erring? 	must I not have erred?
must you not have erred?
must he not have erred?
must we not have erred?
must you not have erred?
must they not have erred? 	must I not have been erring?
must you not have been erring?
must he not have been erring?
must we not have been erring?
must you not have been erring?
must they not have been erring?