can underperform
Regular verb: underperform - underperformed- underperformed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can underperform
you can underperform
he can underperform
we can underperform
you can underperform
they can underperform 	I can be underperforming
you can be underperforming
he can be underperforming
we can be underperforming
you can be underperforming
they can be underperforming	I can have underperformed
you can have underperformed
he can have underperformed
we can have underperformed
you can have underperformed
they can have underperformed	I can have been underperforming
you can have been underperforming
he can have been underperforming
we can have been underperforming
you can have been underperforming
they can have been underperforming	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't underperform
you can't underperform
he can't underperform
we can't underperform
you can't underperform
they can't underperform 	I can't be underperforming
you can't be underperforming
he can't be underperforming
we can't be underperforming
you can't be underperforming
they can't be underperforming	I can't have underperformed
you can't have underperformed
he can't have underperformed
we can't have underperformed
you can't have underperformed
they can't have underperformed	I can't have been underperforming
you can't have been underperforming
he can't have been underperforming
we can't have been underperforming
you can't have been underperforming
they can't have been underperforming	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I underperform?
can you underperform?
can he underperform?
can we underperform?
can you underperform?
can they underperform? 	can I be underperforming?
can you be underperforming?
can he be underperforming?
can we be underperforming?
can you be underperforming?
can they be underperforming? 	can I have underperformed?
can you have underperformed?
can he have underperformed?
can we have underperformed?
can you have underperformed?
can they have underperformed? 	can I have been underperforming?
can you have been underperforming?
can he have been underperforming?
can we have been underperforming?
can you have been underperforming?
can they have been underperforming? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I underperform?
can't you underperform?
can't he underperform?
can't we underperform?
can't you underperform?
can't they underperform? 	can't I be underperforming?
can't you be underperforming?
can't he be underperforming?
can't we be underperforming?
can't you be underperforming?
can't they be underperforming? 	can't I have underperformed?
can't you have underperformed?
can't he have underperformed?
can't we have underperformed?
can't you have underperformed?
can't they have underperformed? 	can't I have been underperforming?
can't you have been underperforming?
can't he have been underperforming?
can't we have been underperforming?
can't you have been underperforming?
can't they have been underperforming?