I could prevalue you could prevalue he could prevalue we could prevalue you could prevalue they could prevalue
V-ing form
I could be prevaluing you could be prevaluing he could be prevaluing we could be prevaluing you could be prevaluing they could be prevaluing
Perfect
I could have prevalued you could have prevalued he could have prevalued we could have prevalued you could have prevalued they could have prevalued
V-ing perfect
I could have been prevaluing you could have been prevaluing he could have been prevaluing we could have been prevaluing you could have been prevaluing they could have been prevaluing
Negation
Simple form
I could not prevalue you could not prevalue he could not prevalue we could not prevalue you could not prevalue they could not prevalue
V-ing form
I could not be prevaluing you could not be prevaluing he could not be prevaluing we could not be prevaluing you could not be prevaluing they could not be prevaluing
Perfect
I could not have prevalued you could not have prevalued he could not have prevalued we could not have prevalued you could not have prevalued they could not have prevalued
V-ing perfect
I could not have been prevaluing you could not have been prevaluing he could not have been prevaluing we could not have been prevaluing you could not have been prevaluing they could not have been prevaluing
Interrogative form
Simple form
could I prevalue? could you prevalue? could he prevalue? could we prevalue? could you prevalue? could they prevalue?
V-ing form
could I be prevaluing? could you be prevaluing? could he be prevaluing? could we be prevaluing? could you be prevaluing? could they be prevaluing?
Perfect
could I have prevalued? could you have prevalued? could he have prevalued? could we have prevalued? could you have prevalued? could they have prevalued?
V-ing perfect
could I have been prevaluing? could you have been prevaluing? could he have been prevaluing? could we have been prevaluing? could you have been prevaluing? could they have been prevaluing?
Interro-negative form
Simple form
could I not prevalue? could you not prevalue? could he not prevalue? could we not prevalue? could you not prevalue? could they not prevalue?
V-ing form
could I not be prevaluing? could you not be prevaluing? could he not be prevaluing? could we not be prevaluing? could you not be prevaluing? could they not be prevaluing?
Perfect
could I not have prevalued? could you not have prevalued? could he not have prevalued? could we not have prevalued? could you not have prevalued? could they not have prevalued?
V-ing perfect
could I not have been prevaluing? could you not have been prevaluing? could he not have been prevaluing? could we not have been prevaluing? could you not have been prevaluing? could they not have been prevaluing?