I must underperform you must underperform she must underperform we must underperform you must underperform they must underperform
V-ing form
I must be underperforming you must be underperforming she must be underperforming we must be underperforming you must be underperforming they must be underperforming
Perfect
I must have underperformed you must have underperformed she must have underperformed we must have underperformed you must have underperformed they must have underperformed
V-ing perfect
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
Negation
Simple form
I must not underperform you must not underperform she must not underperform we must not underperform you must not underperform they must not underperform
V-ing form
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
Perfect
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
V-ing perfect
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
Interrogative form
Simple form
must I underperform? must you underperform? must she underperform? must we underperform? must you underperform? must they underperform?
V-ing form
must I be underperforming? must you be underperforming? must she be underperforming? must we be underperforming? must you be underperforming? must they be underperforming?
Perfect
must I have underperformed? must you have underperformed? must she have underperformed? must we have underperformed? must you have underperformed? must they have underperformed?
V-ing perfect
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?
Interro-negative form
Simple form
must I not underperform? must you not underperform? must she not underperform? must we not underperform? must you not underperform? must they not underperform?
V-ing form
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?
Perfect
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?
V-ing perfect
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?