must underperform
Verbe régulier : underperform - underperformed- underperformed
Traduction française : rester en deçà de ses possibilités 

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must underperform
you must underperform
she must underperform
we must underperform
you must underperform
they must underperform 	I must be underperforming
you must be underperforming
she must be underperforming
we must be underperforming
you must be underperforming
they must be underperforming	I must have underperformed
you must have underperformed
she must have underperformed
we must have underperformed
you must have underperformed
they must have underperformed	I must have been underperforming
you must have been underperforming
she must have been underperforming
we must have been underperforming
you must have been underperforming
they must have been underperforming	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must not underperform
you must not underperform
she must not underperform
we must not underperform
you must not underperform
they must not underperform 	I must not be underperforming
you must not be underperforming
she must not be underperforming
we must not be underperforming
you must not be underperforming
they must not be underperforming	I must not have underperformed
you must not have underperformed
she must not have underperformed
we must not have underperformed
you must not have underperformed
they must not have underperformed	I must not have been underperforming
you must not have been underperforming
she must not have been underperforming
we must not have been underperforming
you must not have been underperforming
they must not have been underperforming	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I underperform?
must you underperform?
must she underperform?
must we underperform?
must you underperform?
must they underperform? 	must I be underperforming?
must you be underperforming?
must she be underperforming?
must we be underperforming?
must you be underperforming?
must they be underperforming? 	must I have underperformed?
must you have underperformed?
must she have underperformed?
must we have underperformed?
must you have underperformed?
must they have underperformed? 	must I have been underperforming?
must you have been underperforming?
must she have been underperforming?
must we have been underperforming?
must you have been underperforming?
must they have been underperforming? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I not underperform?
must you not underperform?
must she not underperform?
must we not underperform?
must you not underperform?
must they not underperform? 	must I not be underperforming?
must you not be underperforming?
must she not be underperforming?
must we not be underperforming?
must you not be underperforming?
must they not be underperforming? 	must I not have underperformed?
must you not have underperformed?
must she not have underperformed?
must we not have underperformed?
must you not have underperformed?
must they not have underperformed? 	must I not have been underperforming?
must you not have been underperforming?
must she not have been underperforming?
must we not have been underperforming?
must you not have been underperforming?
must they not have been underperforming?