I could forestall you could forestall she could forestall we could forestall you could forestall they could forestall
V-ing form
I could be forestalling you could be forestalling she could be forestalling we could be forestalling you could be forestalling they could be forestalling
Perfect
I could have forestalled you could have forestalled she could have forestalled we could have forestalled you could have forestalled they could have forestalled
V-ing perfect
I could have been forestalling you could have been forestalling she could have been forestalling we could have been forestalling you could have been forestalling they could have been forestalling
Negation
Simple form
I could not forestall you could not forestall she could not forestall we could not forestall you could not forestall they could not forestall
V-ing form
I could not be forestalling you could not be forestalling she could not be forestalling we could not be forestalling you could not be forestalling they could not be forestalling
Perfect
I could not have forestalled you could not have forestalled she could not have forestalled we could not have forestalled you could not have forestalled they could not have forestalled
V-ing perfect
I could not have been forestalling you could not have been forestalling she could not have been forestalling we could not have been forestalling you could not have been forestalling they could not have been forestalling
Interrogative form
Simple form
could I forestall? could you forestall? could she forestall? could we forestall? could you forestall? could they forestall?
V-ing form
could I be forestalling? could you be forestalling? could she be forestalling? could we be forestalling? could you be forestalling? could they be forestalling?
Perfect
could I have forestalled? could you have forestalled? could she have forestalled? could we have forestalled? could you have forestalled? could they have forestalled?
V-ing perfect
could I have been forestalling? could you have been forestalling? could she have been forestalling? could we have been forestalling? could you have been forestalling? could they have been forestalling?
Interro-negative form
Simple form
could I not forestall? could you not forestall? could she not forestall? could we not forestall? could you not forestall? could they not forestall?
V-ing form
could I not be forestalling? could you not be forestalling? could she not be forestalling? could we not be forestalling? could you not be forestalling? could they not be forestalling?
Perfect
could I not have forestalled? could you not have forestalled? could she not have forestalled? could we not have forestalled? could you not have forestalled? could they not have forestalled?
V-ing perfect
could I not have been forestalling? could you not have been forestalling? could she not have been forestalling? could we not have been forestalling? could you not have been forestalling? could they not have been forestalling?