would underpin
Regular verb: underpin - underpinned- underpinned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd underpin
you'd underpin
she'd underpin
we'd underpin
you'd underpin
they'd underpin 	I'd be underpinning
you'd be underpinning
she'd be underpinning
we'd be underpinning
you'd be underpinning
they'd be underpinning	I would've underpinned
you would've underpinned
she would've underpinned
we would've underpinned
you would've underpinned
they would've underpinned	I would've been underpinning
you would've been underpinning
she would've been underpinning
we would've been underpinning
you would've been underpinning
they would've been underpinning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I wouldn't underpin
you wouldn't underpin
she wouldn't underpin
we wouldn't underpin
you wouldn't underpin
they wouldn't underpin 	I wouldn't be underpinning
you wouldn't be underpinning
she wouldn't be underpinning
we wouldn't be underpinning
you wouldn't be underpinning
they wouldn't be underpinning	I wouldn't have underpinned
you wouldn't have underpinned
she wouldn't have underpinned
we wouldn't have underpinned
you wouldn't have underpinned
they wouldn't have underpinned	I wouldn't have been underpinning
you wouldn't have been underpinning
she wouldn't have been underpinning
we wouldn't have been underpinning
you wouldn't have been underpinning
they wouldn't have been underpinning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
would I underpin?
would you underpin?
would she underpin?
would we underpin?
would you underpin?
would they underpin? 	would I be underpinning?
would you be underpinning?
would she be underpinning?
would we be underpinning?
would you be underpinning?
would they be underpinning? 	would I have underpinned?
would you have underpinned?
would she have underpinned?
would we have underpinned?
would you have underpinned?
would they have underpinned? 	would I have been underpinning?
would you have been underpinning?
would she have been underpinning?
would we have been underpinning?
would you have been underpinning?
would they have been underpinning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
wouldn't I underpin?
wouldn't you underpin?
wouldn't she underpin?
wouldn't we underpin?
wouldn't you underpin?
wouldn't they underpin? 	wouldn't I be underpinning?
wouldn't you be underpinning?
wouldn't she be underpinning?
wouldn't we be underpinning?
wouldn't you be underpinning?
wouldn't they be underpinning? 	wouldn't I have underpinned?
wouldn't you have underpinned?
wouldn't she have underpinned?
wouldn't we have underpinned?
wouldn't you have underpinned?
wouldn't they have underpinned? 	wouldn't I have been underpinning?
wouldn't you have been underpinning?
wouldn't she have been underpinning?
wouldn't we have been underpinning?
wouldn't you have been underpinning?
wouldn't they have been underpinning?