I could underexercise you could underexercise he could underexercise we could underexercise you could underexercise they could underexercise
V-ing form
I could be underexercising you could be underexercising he could be underexercising we could be underexercising you could be underexercising they could be underexercising
Perfect
I could have underexercised you could have underexercised he could have underexercised we could have underexercised you could have underexercised they could have underexercised
V-ing perfect
I could have been underexercising you could have been underexercising he could have been underexercising we could have been underexercising you could have been underexercising they could have been underexercising
Negation
Simple form
I couldn't underexercise you couldn't underexercise he couldn't underexercise we couldn't underexercise you couldn't underexercise they couldn't underexercise
V-ing form
I couldn't be underexercising you couldn't be underexercising he couldn't be underexercising we couldn't be underexercising you couldn't be underexercising they couldn't be underexercising
Perfect
I couldn't have underexercised you couldn't have underexercised he couldn't have underexercised we couldn't have underexercised you couldn't have underexercised they couldn't have underexercised
V-ing perfect
I couldn't have been underexercising you couldn't have been underexercising he couldn't have been underexercising we couldn't have been underexercising you couldn't have been underexercising they couldn't have been underexercising
Interrogative form
Simple form
could I underexercise? could you underexercise? could he underexercise? could we underexercise? could you underexercise? could they underexercise?
V-ing form
could I be underexercising? could you be underexercising? could he be underexercising? could we be underexercising? could you be underexercising? could they be underexercising?
Perfect
could I have underexercised? could you have underexercised? could he have underexercised? could we have underexercised? could you have underexercised? could they have underexercised?
V-ing perfect
could I have been underexercising? could you have been underexercising? could he have been underexercising? could we have been underexercising? could you have been underexercising? could they have been underexercising?
Interro-negative form
Simple form
couldn't I underexercise? couldn't you underexercise? couldn't he underexercise? couldn't we underexercise? couldn't you underexercise? couldn't they underexercise?
V-ing form
couldn't I be underexercising? couldn't you be underexercising? couldn't he be underexercising? couldn't we be underexercising? couldn't you be underexercising? couldn't they be underexercising?
Perfect
couldn't I have underexercised? couldn't you have underexercised? couldn't he have underexercised? couldn't we have underexercised? couldn't you have underexercised? couldn't they have underexercised?
V-ing perfect
couldn't I have been underexercising? couldn't you have been underexercising? couldn't he have been underexercising? couldn't we have been underexercising? couldn't you have been underexercising? couldn't they have been underexercising?