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