must underpin
Verbe régulier : underpin - underpinned- underpinned
Traduction française : soutenir - étayer 

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I must underpin
you must underpin
she must underpin
we must underpin
you must underpin
they must underpin 	I must be underpinning
you must be underpinning
she must be underpinning
we must be underpinning
you must be underpinning
they must be underpinning	I must have underpinned
you must have underpinned
she must have underpinned
we must have underpinned
you must have underpinned
they must have underpinned	I must have been underpinning
you must have been underpinning
she must have been underpinning
we must have been underpinning
you must have been underpinning
they must have been underpinning	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I mustn't underpin
you mustn't underpin
she mustn't underpin
we mustn't underpin
you mustn't underpin
they mustn't underpin 	I mustn't be underpinning
you mustn't be underpinning
she mustn't be underpinning
we mustn't be underpinning
you mustn't be underpinning
they mustn't be underpinning	I mustn't have underpinned
you mustn't have underpinned
she mustn't have underpinned
we mustn't have underpinned
you mustn't have underpinned
they mustn't have underpinned	I mustn't have been underpinning
you mustn't have been underpinning
she mustn't have been underpinning
we mustn't have been underpinning
you mustn't have been underpinning
they mustn't have been underpinning	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
must I underpin?
must you underpin?
must she underpin?
must we underpin?
must you underpin?
must they underpin? 	must I be underpinning?
must you be underpinning?
must she be underpinning?
must we be underpinning?
must you be underpinning?
must they be underpinning? 	must I have underpinned?
must you have underpinned?
must she have underpinned?
must we have underpinned?
must you have underpinned?
must they have underpinned? 	must I have been underpinning?
must you have been underpinning?
must she have been underpinning?
must we have been underpinning?
must you have been underpinning?
must they have been underpinning? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
mustn't I underpin?
mustn't you underpin?
mustn't she underpin?
mustn't we underpin?
mustn't you underpin?
mustn't they underpin? 	mustn't I be underpinning?
mustn't you be underpinning?
mustn't she be underpinning?
mustn't we be underpinning?
mustn't you be underpinning?
mustn't they be underpinning? 	mustn't I have underpinned?
mustn't you have underpinned?
mustn't she have underpinned?
mustn't we have underpinned?
mustn't you have underpinned?
mustn't they have underpinned? 	mustn't I have been underpinning?
mustn't you have been underpinning?
mustn't she have been underpinning?
mustn't we have been underpinning?
mustn't you have been underpinning?
mustn't they have been underpinning?