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