English verb conjugation
COULD SLIPPER

Regular verb: slipper - slippered - slippered

Affirmation

Simple form	V-ing form
I could slipper you could slipper he could slipper we could slipper you could slipper they could slipper	I could be slippering you could be slippering he could be slippering we could be slippering you could be slippering they could be slippering
Perfect	V-ing perfect
I could have slippered you could have slippered he could have slippered we could have slippered you could have slippered they could have slippered	I could have been slippering you could have been slippering he could have been slippering we could have been slippering you could have been slippering they could have been slippering

Negation

Simple form	V-ing form
I couldn't slipper you couldn't slipper he couldn't slipper we couldn't slipper you couldn't slipper they couldn't slipper	I couldn't be slippering you couldn't be slippering he couldn't be slippering we couldn't be slippering you couldn't be slippering they couldn't be slippering
Perfect	V-ing perfect
I couldn't have slippered you couldn't have slippered he couldn't have slippered we couldn't have slippered you couldn't have slippered they couldn't have slippered	I couldn't have been slippering you couldn't have been slippering he couldn't have been slippering we couldn't have been slippering you couldn't have been slippering they couldn't have been slippering

Interrogative form

Simple form	V-ing form
could I slipper? could you slipper? could he slipper? could we slipper? could you slipper? could they slipper?	could I be slippering? could you be slippering? could he be slippering? could we be slippering? could you be slippering? could they be slippering?
Perfect	V-ing perfect
could I have slippered? could you have slippered? could he have slippered? could we have slippered? could you have slippered? could they have slippered?	could I have been slippering? could you have been slippering? could he have been slippering? could we have been slippering? could you have been slippering? could they have been slippering?

Interro-negative form

Simple form	V-ing form
couldn't I slipper? couldn't you slipper? couldn't he slipper? couldn't we slipper? couldn't you slipper? couldn't they slipper?	couldn't I be slippering? couldn't you be slippering? couldn't he be slippering? couldn't we be slippering? couldn't you be slippering? couldn't they be slippering?
Perfect	V-ing perfect
couldn't I have slippered? couldn't you have slippered? couldn't he have slippered? couldn't we have slippered? couldn't you have slippered? couldn't they have slippered?	couldn't I have been slippering? couldn't you have been slippering? couldn't he have been slippering? couldn't we have been slippering? couldn't you have been slippering? couldn't they have been slippering?