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