must underperform
Regular verb: underperform - underperformed- underperformed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must underperform
you must underperform
he must underperform
we must underperform
you must underperform
they must underperform 	I must be underperforming
you must be underperforming
he must be underperforming
we must be underperforming
you must be underperforming
they must be underperforming	I must have underperformed
you must have underperformed
he 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
he must have been underperforming
we must have been underperforming
you must have been underperforming
they must have been underperforming	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must not underperform
you must not underperform
he 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
he 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
he 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
he must not have been underperforming
we must not have been underperforming
you must not have been underperforming
they must not have been underperforming	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I underperform?
must you underperform?
must he underperform?
must we underperform?
must you underperform?
must they underperform? 	must I be underperforming?
must you be underperforming?
must he be underperforming?
must we be underperforming?
must you be underperforming?
must they be underperforming? 	must I have underperformed?
must you have underperformed?
must he 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 he have been underperforming?
must we have been underperforming?
must you have been underperforming?
must they have been underperforming? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I not underperform?
must you not underperform?
must he 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 he 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 he 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 he not have been underperforming?
must we not have been underperforming?
must you not have been underperforming?
must they not have been underperforming?