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