English verb conjugation
MUST UNDERPERFORM

Regular verb: underperform - underperformed - underperformed

Affirmation

Simple form	V-ing form
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
Perfect	V-ing 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	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	V-ing form
I mustn't underperform you mustn't underperform she mustn't underperform we mustn't underperform you mustn't underperform they mustn't underperform	I mustn't be underperforming you mustn't be underperforming she mustn't be underperforming we mustn't be underperforming you mustn't be underperforming they mustn't be underperforming
Perfect	V-ing perfect
I mustn't have underperformed you mustn't have underperformed she mustn't have underperformed we mustn't have underperformed you mustn't have underperformed they mustn't have underperformed	I mustn't have been underperforming you mustn't have been underperforming she mustn't have been underperforming we mustn't have been underperforming you mustn't have been underperforming they mustn't have been underperforming

Interrogative form

Simple form	V-ing form
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?
Perfect	V-ing 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?	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	V-ing form
mustn't I underperform? mustn't you underperform? mustn't she underperform? mustn't we underperform? mustn't you underperform? mustn't they underperform?	mustn't I be underperforming? mustn't you be underperforming? mustn't she be underperforming? mustn't we be underperforming? mustn't you be underperforming? mustn't they be underperforming?
Perfect	V-ing perfect
mustn't I have underperformed? mustn't you have underperformed? mustn't she have underperformed? mustn't we have underperformed? mustn't you have underperformed? mustn't they have underperformed?	mustn't I have been underperforming? mustn't you have been underperforming? mustn't she have been underperforming? mustn't we have been underperforming? mustn't you have been underperforming? mustn't they have been underperforming?