I could discolor you could discolor he could discolor we could discolor you could discolor they could discolor
V-ing form
I could be discoloring you could be discoloring he could be discoloring we could be discoloring you could be discoloring they could be discoloring
Perfect
I could have discolored you could have discolored he could have discolored we could have discolored you could have discolored they could have discolored
V-ing perfect
I could have been discoloring you could have been discoloring he could have been discoloring we could have been discoloring you could have been discoloring they could have been discoloring
Negation
Simple form
I could not discolor you could not discolor he could not discolor we could not discolor you could not discolor they could not discolor
V-ing form
I could not be discoloring you could not be discoloring he could not be discoloring we could not be discoloring you could not be discoloring they could not be discoloring
Perfect
I could not have discolored you could not have discolored he could not have discolored we could not have discolored you could not have discolored they could not have discolored
V-ing perfect
I could not have been discoloring you could not have been discoloring he could not have been discoloring we could not have been discoloring you could not have been discoloring they could not have been discoloring
Interrogative form
Simple form
could I discolor? could you discolor? could he discolor? could we discolor? could you discolor? could they discolor?
V-ing form
could I be discoloring? could you be discoloring? could he be discoloring? could we be discoloring? could you be discoloring? could they be discoloring?
Perfect
could I have discolored? could you have discolored? could he have discolored? could we have discolored? could you have discolored? could they have discolored?
V-ing perfect
could I have been discoloring? could you have been discoloring? could he have been discoloring? could we have been discoloring? could you have been discoloring? could they have been discoloring?
Interro-negative form
Simple form
could I not discolor? could you not discolor? could he not discolor? could we not discolor? could you not discolor? could they not discolor?
V-ing form
could I not be discoloring? could you not be discoloring? could he not be discoloring? could we not be discoloring? could you not be discoloring? could they not be discoloring?
Perfect
could I not have discolored? could you not have discolored? could he not have discolored? could we not have discolored? could you not have discolored? could they not have discolored?
V-ing perfect
could I not have been discoloring? could you not have been discoloring? could he not have been discoloring? could we not have been discoloring? could you not have been discoloring? could they not have been discoloring?