English verb conjugation
SHOULD UNDERUSE

Regular verb: underuse - underused - underused

Affirmation

Simple form	V-ing form
I'd underuse you'd underuse he'd underuse we'd underuse you'd underuse they'd underuse	I'd be underusing you'd be underusing he'd be underusing we'd be underusing you'd be underusing they'd be underusing
Perfect	V-ing perfect
I should've underused you should've underused he should've underused we should've underused you should've underused they should've underused	I should've been underusing you should've been underusing he should've been underusing we should've been underusing you should've been underusing they should've been underusing

Negation

Simple form	V-ing form
I shouldn't underuse you shouldn't underuse he shouldn't underuse we shouldn't underuse you shouldn't underuse they shouldn't underuse	I shouldn't be underusing you shouldn't be underusing he shouldn't be underusing we shouldn't be underusing you shouldn't be underusing they shouldn't be underusing
Perfect	V-ing perfect
I shouldn't have underused you shouldn't have underused he shouldn't have underused we shouldn't have underused you shouldn't have underused they shouldn't have underused	I shouldn't have been underusing you shouldn't have been underusing he shouldn't have been underusing we shouldn't have been underusing you shouldn't have been underusing they shouldn't have been underusing

Interrogative form

Simple form	V-ing form
should I underuse? should you underuse? should he underuse? should we underuse? should you underuse? should they underuse?	should I be underusing? should you be underusing? should he be underusing? should we be underusing? should you be underusing? should they be underusing?
Perfect	V-ing perfect
should I have underused? should you have underused? should he have underused? should we have underused? should you have underused? should they have underused?	should I have been underusing? should you have been underusing? should he have been underusing? should we have been underusing? should you have been underusing? should they have been underusing?

Interro-negative form

Simple form	V-ing form
shouldn't I underuse? shouldn't you underuse? shouldn't he underuse? shouldn't we underuse? shouldn't you underuse? shouldn't they underuse?	shouldn't I be underusing? shouldn't you be underusing? shouldn't he be underusing? shouldn't we be underusing? shouldn't you be underusing? shouldn't they be underusing?
Perfect	V-ing perfect
shouldn't I have underused? shouldn't you have underused? shouldn't he have underused? shouldn't we have underused? shouldn't you have underused? shouldn't they have underused?	shouldn't I have been underusing? shouldn't you have been underusing? shouldn't he have been underusing? shouldn't we have been underusing? shouldn't you have been underusing? shouldn't they have been underusing?