English verb conjugation
COULD KNUCKLE

Regular verb: knuckle - knuckled - knuckled

Affirmation

Simple form	V-ing form
I could knuckle you could knuckle he could knuckle we could knuckle you could knuckle they could knuckle	I could be knuckling you could be knuckling he could be knuckling we could be knuckling you could be knuckling they could be knuckling
Perfect	V-ing perfect
I could have knuckled you could have knuckled he could have knuckled we could have knuckled you could have knuckled they could have knuckled	I could have been knuckling you could have been knuckling he could have been knuckling we could have been knuckling you could have been knuckling they could have been knuckling

Negation

Simple form	V-ing form
I could not knuckle you could not knuckle he could not knuckle we could not knuckle you could not knuckle they could not knuckle	I could not be knuckling you could not be knuckling he could not be knuckling we could not be knuckling you could not be knuckling they could not be knuckling
Perfect	V-ing perfect
I could not have knuckled you could not have knuckled he could not have knuckled we could not have knuckled you could not have knuckled they could not have knuckled	I could not have been knuckling you could not have been knuckling he could not have been knuckling we could not have been knuckling you could not have been knuckling they could not have been knuckling

Interrogative form

Simple form	V-ing form
could I knuckle? could you knuckle? could he knuckle? could we knuckle? could you knuckle? could they knuckle?	could I be knuckling? could you be knuckling? could he be knuckling? could we be knuckling? could you be knuckling? could they be knuckling?
Perfect	V-ing perfect
could I have knuckled? could you have knuckled? could he have knuckled? could we have knuckled? could you have knuckled? could they have knuckled?	could I have been knuckling? could you have been knuckling? could he have been knuckling? could we have been knuckling? could you have been knuckling? could they have been knuckling?

Interro-negative form

Simple form	V-ing form
could I not knuckle? could you not knuckle? could he not knuckle? could we not knuckle? could you not knuckle? could they not knuckle?	could I not be knuckling? could you not be knuckling? could he not be knuckling? could we not be knuckling? could you not be knuckling? could they not be knuckling?
Perfect	V-ing perfect
could I not have knuckled? could you not have knuckled? could he not have knuckled? could we not have knuckled? could you not have knuckled? could they not have knuckled?	could I not have been knuckling? could you not have been knuckling? could he not have been knuckling? could we not have been knuckling? could you not have been knuckling? could they not have been knuckling?