English verb conjugation
CAN KNUCKLE

Regular verb: knuckle - knuckled - knuckled

Affirmation

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

Negation

Simple form	V-ing form
I can't knuckle you can't knuckle he can't knuckle we can't knuckle you can't knuckle they can't knuckle	I can't be knuckling you can't be knuckling he can't be knuckling we can't be knuckling you can't be knuckling they can't be knuckling
Perfect	V-ing perfect
I can't have knuckled you can't have knuckled he can't have knuckled we can't have knuckled you can't have knuckled they can't have knuckled	I can't have been knuckling you can't have been knuckling he can't have been knuckling we can't have been knuckling you can't have been knuckling they can't have been knuckling

Interrogative form

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

Interro-negative form

Simple form	V-ing form
can't I knuckle? can't you knuckle? can't he knuckle? can't we knuckle? can't you knuckle? can't they knuckle?	can't I be knuckling? can't you be knuckling? can't he be knuckling? can't we be knuckling? can't you be knuckling? can't they be knuckling?
Perfect	V-ing perfect
can't I have knuckled? can't you have knuckled? can't he have knuckled? can't we have knuckled? can't you have knuckled? can't they have knuckled?	can't I have been knuckling? can't you have been knuckling? can't he have been knuckling? can't we have been knuckling? can't you have been knuckling? can't they have been knuckling?