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