I could sizzle you could sizzle he could sizzle we could sizzle you could sizzle they could sizzle
V-ing form
I could be sizzling you could be sizzling he could be sizzling we could be sizzling you could be sizzling they could be sizzling
Perfect
I could have sizzled you could have sizzled he could have sizzled we could have sizzled you could have sizzled they could have sizzled
V-ing perfect
I could have been sizzling you could have been sizzling he could have been sizzling we could have been sizzling you could have been sizzling they could have been sizzling
Negation
Simple form
I could not sizzle you could not sizzle he could not sizzle we could not sizzle you could not sizzle they could not sizzle
V-ing form
I could not be sizzling you could not be sizzling he could not be sizzling we could not be sizzling you could not be sizzling they could not be sizzling
Perfect
I could not have sizzled you could not have sizzled he could not have sizzled we could not have sizzled you could not have sizzled they could not have sizzled
V-ing perfect
I could not have been sizzling you could not have been sizzling he could not have been sizzling we could not have been sizzling you could not have been sizzling they could not have been sizzling
Interrogative form
Simple form
could I sizzle? could you sizzle? could he sizzle? could we sizzle? could you sizzle? could they sizzle?
V-ing form
could I be sizzling? could you be sizzling? could he be sizzling? could we be sizzling? could you be sizzling? could they be sizzling?
Perfect
could I have sizzled? could you have sizzled? could he have sizzled? could we have sizzled? could you have sizzled? could they have sizzled?
V-ing perfect
could I have been sizzling? could you have been sizzling? could he have been sizzling? could we have been sizzling? could you have been sizzling? could they have been sizzling?
Interro-negative form
Simple form
could I not sizzle? could you not sizzle? could he not sizzle? could we not sizzle? could you not sizzle? could they not sizzle?
V-ing form
could I not be sizzling? could you not be sizzling? could he not be sizzling? could we not be sizzling? could you not be sizzling? could they not be sizzling?
Perfect
could I not have sizzled? could you not have sizzled? could he not have sizzled? could we not have sizzled? could you not have sizzled? could they not have sizzled?
V-ing perfect
could I not have been sizzling? could you not have been sizzling? could he not have been sizzling? could we not have been sizzling? could you not have been sizzling? could they not have been sizzling?