English verb conjugation
MUST UNDERPROP

Regular verb: underprop - underproped - underproped

Affirmation

Simple form	V-ing form
I must underprop you must underprop he must underprop we must underprop you must underprop they must underprop	I must be underproping you must be underproping he must be underproping we must be underproping you must be underproping they must be underproping
Perfect	V-ing perfect
I must have underproped you must have underproped he must have underproped we must have underproped you must have underproped they must have underproped	I must have been underproping you must have been underproping he must have been underproping we must have been underproping you must have been underproping they must have been underproping

Negation

Simple form	V-ing form
I mustn't underprop you mustn't underprop he mustn't underprop we mustn't underprop you mustn't underprop they mustn't underprop	I mustn't be underproping you mustn't be underproping he mustn't be underproping we mustn't be underproping you mustn't be underproping they mustn't be underproping
Perfect	V-ing perfect
I mustn't have underproped you mustn't have underproped he mustn't have underproped we mustn't have underproped you mustn't have underproped they mustn't have underproped	I mustn't have been underproping you mustn't have been underproping he mustn't have been underproping we mustn't have been underproping you mustn't have been underproping they mustn't have been underproping

Interrogative form

Simple form	V-ing form
must I underprop? must you underprop? must he underprop? must we underprop? must you underprop? must they underprop?	must I be underproping? must you be underproping? must he be underproping? must we be underproping? must you be underproping? must they be underproping?
Perfect	V-ing perfect
must I have underproped? must you have underproped? must he have underproped? must we have underproped? must you have underproped? must they have underproped?	must I have been underproping? must you have been underproping? must he have been underproping? must we have been underproping? must you have been underproping? must they have been underproping?

Interro-negative form

Simple form	V-ing form
mustn't I underprop? mustn't you underprop? mustn't he underprop? mustn't we underprop? mustn't you underprop? mustn't they underprop?	mustn't I be underproping? mustn't you be underproping? mustn't he be underproping? mustn't we be underproping? mustn't you be underproping? mustn't they be underproping?
Perfect	V-ing perfect
mustn't I have underproped? mustn't you have underproped? mustn't he have underproped? mustn't we have underproped? mustn't you have underproped? mustn't they have underproped?	mustn't I have been underproping? mustn't you have been underproping? mustn't he have been underproping? mustn't we have been underproping? mustn't you have been underproping? mustn't they have been underproping?