I could slum you could slum she could slum we could slum you could slum they could slum
V-ing form
I could be sluming you could be sluming she could be sluming we could be sluming you could be sluming they could be sluming
Perfect
I could have slumed you could have slumed she could have slumed we could have slumed you could have slumed they could have slumed
V-ing perfect
I could have been sluming you could have been sluming she could have been sluming we could have been sluming you could have been sluming they could have been sluming
Negation
Simple form
I couldn't slum you couldn't slum she couldn't slum we couldn't slum you couldn't slum they couldn't slum
V-ing form
I couldn't be sluming you couldn't be sluming she couldn't be sluming we couldn't be sluming you couldn't be sluming they couldn't be sluming
Perfect
I couldn't have slumed you couldn't have slumed she couldn't have slumed we couldn't have slumed you couldn't have slumed they couldn't have slumed
V-ing perfect
I couldn't have been sluming you couldn't have been sluming she couldn't have been sluming we couldn't have been sluming you couldn't have been sluming they couldn't have been sluming
Interrogative form
Simple form
could I slum? could you slum? could she slum? could we slum? could you slum? could they slum?
V-ing form
could I be sluming? could you be sluming? could she be sluming? could we be sluming? could you be sluming? could they be sluming?
Perfect
could I have slumed? could you have slumed? could she have slumed? could we have slumed? could you have slumed? could they have slumed?
V-ing perfect
could I have been sluming? could you have been sluming? could she have been sluming? could we have been sluming? could you have been sluming? could they have been sluming?
Interro-negative form
Simple form
couldn't I slum? couldn't you slum? couldn't she slum? couldn't we slum? couldn't you slum? couldn't they slum?
V-ing form
couldn't I be sluming? couldn't you be sluming? couldn't she be sluming? couldn't we be sluming? couldn't you be sluming? couldn't they be sluming?
Perfect
couldn't I have slumed? couldn't you have slumed? couldn't she have slumed? couldn't we have slumed? couldn't you have slumed? couldn't they have slumed?
V-ing perfect
couldn't I have been sluming? couldn't you have been sluming? couldn't she have been sluming? couldn't we have been sluming? couldn't you have been sluming? couldn't they have been sluming?