English verb conjugation
CAN UNDERUSE

Regular verb: underuse - underused - underused

Affirmation

Simple form	V-ing form
I can underuse you can underuse she can underuse we can underuse you can underuse they can underuse	I can be underusing you can be underusing she can be underusing we can be underusing you can be underusing they can be underusing
Perfect	V-ing perfect
I can have underused you can have underused she can have underused we can have underused you can have underused they can have underused	I can have been underusing you can have been underusing she can have been underusing we can have been underusing you can have been underusing they can have been underusing

Negation

Simple form	V-ing form
I cannot underuse you cannot underuse she cannot underuse we cannot underuse you cannot underuse they cannot underuse	I cannot be underusing you cannot be underusing she cannot be underusing we cannot be underusing you cannot be underusing they cannot be underusing
Perfect	V-ing perfect
I cannot have underused you cannot have underused she cannot have underused we cannot have underused you cannot have underused they cannot have underused	I cannot have been underusing you cannot have been underusing she cannot have been underusing we cannot have been underusing you cannot have been underusing they cannot have been underusing

Interrogative form

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

Interro-negative form

Simple form	V-ing form
can I not underuse? can you not underuse? can she not underuse? can we not underuse? can you not underuse? can they not underuse?	can I not be underusing? can you not be underusing? can she not be underusing? can we not be underusing? can you not be underusing? can they not be underusing?
Perfect	V-ing perfect
can I not have underused? can you not have underused? can she not have underused? can we not have underused? can you not have underused? can they not have underused?	can I not have been underusing? can you not have been underusing? can she not have been underusing? can we not have been underusing? can you not have been underusing? can they not have been underusing?