English verb conjugation
COULD SLIPPER

Regular verb: slipper - slippered - slippered

Affirmation

Simple form	V-ing form
I could slipper you could slipper she could slipper we could slipper you could slipper they could slipper	I could be slippering you could be slippering she 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 she 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 she 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 she 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 she 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 she 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 she 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 she slipper? could we slipper? could you slipper? could they slipper?	could I be slippering? could you be slippering? could she 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 she 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 she 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 she 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 she 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 she 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 she have been slippering? couldn't we have been slippering? couldn't you have been slippering? couldn't they have been slippering?