English verb conjugation
CAN UNDERPIN

Regular verb: underpin - underpinned - underpinned

Affirmation

Simple form	V-ing form
I can underpin you can underpin he can underpin we can underpin you can underpin they can underpin	I can be underpinning you can be underpinning he can be underpinning we can be underpinning you can be underpinning they can be underpinning
Perfect	V-ing perfect
I can have underpinned you can have underpinned he can have underpinned we can have underpinned you can have underpinned they can have underpinned	I can have been underpinning you can have been underpinning he can have been underpinning we can have been underpinning you can have been underpinning they can have been underpinning

Negation

Simple form	V-ing form
I can't underpin you can't underpin he can't underpin we can't underpin you can't underpin they can't underpin	I can't be underpinning you can't be underpinning he can't be underpinning we can't be underpinning you can't be underpinning they can't be underpinning
Perfect	V-ing perfect
I can't have underpinned you can't have underpinned he can't have underpinned we can't have underpinned you can't have underpinned they can't have underpinned	I can't have been underpinning you can't have been underpinning he can't have been underpinning we can't have been underpinning you can't have been underpinning they can't have been underpinning

Interrogative form

Simple form	V-ing form
can I underpin? can you underpin? can he underpin? can we underpin? can you underpin? can they underpin?	can I be underpinning? can you be underpinning? can he be underpinning? can we be underpinning? can you be underpinning? can they be underpinning?
Perfect	V-ing perfect
can I have underpinned? can you have underpinned? can he have underpinned? can we have underpinned? can you have underpinned? can they have underpinned?	can I have been underpinning? can you have been underpinning? can he have been underpinning? can we have been underpinning? can you have been underpinning? can they have been underpinning?

Interro-negative form

Simple form	V-ing form
can't I underpin? can't you underpin? can't he underpin? can't we underpin? can't you underpin? can't they underpin?	can't I be underpinning? can't you be underpinning? can't he be underpinning? can't we be underpinning? can't you be underpinning? can't they be underpinning?
Perfect	V-ing perfect
can't I have underpinned? can't you have underpinned? can't he have underpinned? can't we have underpinned? can't you have underpinned? can't they have underpinned?	can't I have been underpinning? can't you have been underpinning? can't he have been underpinning? can't we have been underpinning? can't you have been underpinning? can't they have been underpinning?