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