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