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