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