must underprop
Verbe régulier : underprop - underproped- underproped

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must underprop
you must underprop
she must underprop
we must underprop
you must underprop
they must underprop 	I must be underproping
you must be underproping
she must be underproping
we must be underproping
you must be underproping
they must be underproping	I must have underproped
you must have underproped
she 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
she must have been underproping
we must have been underproping
you must have been underproping
they must have been underproping	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't underprop
you mustn't underprop
she 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
she mustn't be underproping
we mustn't be underproping
you mustn't be underproping
they mustn't be underproping	I mustn't have underproped
you mustn't have underproped
she 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
she mustn't have been underproping
we mustn't have been underproping
you mustn't have been underproping
they mustn't have been underproping	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I underprop?
must you underprop?
must she underprop?
must we underprop?
must you underprop?
must they underprop? 	must I be underproping?
must you be underproping?
must she be underproping?
must we be underproping?
must you be underproping?
must they be underproping? 	must I have underproped?
must you have underproped?
must she 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 she have been underproping?
must we have been underproping?
must you have been underproping?
must they have been underproping? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I underprop?
mustn't you underprop?
mustn't she 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 she be underproping?
mustn't we be underproping?
mustn't you be underproping?
mustn't they be underproping? 	mustn't I have underproped?
mustn't you have underproped?
mustn't she 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 she have been underproping?
mustn't we have been underproping?
mustn't you have been underproping?
mustn't they have been underproping?