must underuse
Verbo regular: underuse - underused- underused

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must underuse
you must underuse
he must underuse
we must underuse
you must underuse
they must underuse 	I must be underusing
you must be underusing
he must be underusing
we must be underusing
you must be underusing
they must be underusing	I must have underused
you must have underused
he must have underused
we must have underused
you must have underused
they must have underused	I must have been underusing
you must have been underusing
he must have been underusing
we must have been underusing
you must have been underusing
they must have been underusing	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I must not underuse
you must not underuse
he must not underuse
we must not underuse
you must not underuse
they must not underuse 	I must not be underusing
you must not be underusing
he must not be underusing
we must not be underusing
you must not be underusing
they must not be underusing	I must not have underused
you must not have underused
he must not have underused
we must not have underused
you must not have underused
they must not have underused	I must not have been underusing
you must not have been underusing
he must not have been underusing
we must not have been underusing
you must not have been underusing
they must not have been underusing	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I underuse?
must you underuse?
must he underuse?
must we underuse?
must you underuse?
must they underuse? 	must I be underusing?
must you be underusing?
must he be underusing?
must we be underusing?
must you be underusing?
must they be underusing? 	must I have underused?
must you have underused?
must he have underused?
must we have underused?
must you have underused?
must they have underused? 	must I have been underusing?
must you have been underusing?
must he have been underusing?
must we have been underusing?
must you have been underusing?
must they have been underusing? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
must I not underuse?
must you not underuse?
must he not underuse?
must we not underuse?
must you not underuse?
must they not underuse? 	must I not be underusing?
must you not be underusing?
must he not be underusing?
must we not be underusing?
must you not be underusing?
must they not be underusing? 	must I not have underused?
must you not have underused?
must he not have underused?
must we not have underused?
must you not have underused?
must they not have underused? 	must I not have been underusing?
must you not have been underusing?
must he not have been underusing?
must we not have been underusing?
must you not have been underusing?
must they not have been underusing?