English verb conjugation
COULD KNURL

Regular verb: knurl - knurled - knurled

Affirmation

Simple form	V-ing form
I could knurl you could knurl he could knurl we could knurl you could knurl they could knurl	I could be knurling you could be knurling he could be knurling we could be knurling you could be knurling they could be knurling
Perfect	V-ing perfect
I could have knurled you could have knurled he could have knurled we could have knurled you could have knurled they could have knurled	I could have been knurling you could have been knurling he could have been knurling we could have been knurling you could have been knurling they could have been knurling

Negation

Simple form	V-ing form
I could not knurl you could not knurl he could not knurl we could not knurl you could not knurl they could not knurl	I could not be knurling you could not be knurling he could not be knurling we could not be knurling you could not be knurling they could not be knurling
Perfect	V-ing perfect
I could not have knurled you could not have knurled he could not have knurled we could not have knurled you could not have knurled they could not have knurled	I could not have been knurling you could not have been knurling he could not have been knurling we could not have been knurling you could not have been knurling they could not have been knurling

Interrogative form

Simple form	V-ing form
could I knurl? could you knurl? could he knurl? could we knurl? could you knurl? could they knurl?	could I be knurling? could you be knurling? could he be knurling? could we be knurling? could you be knurling? could they be knurling?
Perfect	V-ing perfect
could I have knurled? could you have knurled? could he have knurled? could we have knurled? could you have knurled? could they have knurled?	could I have been knurling? could you have been knurling? could he have been knurling? could we have been knurling? could you have been knurling? could they have been knurling?

Interro-negative form

Simple form	V-ing form
could I not knurl? could you not knurl? could he not knurl? could we not knurl? could you not knurl? could they not knurl?	could I not be knurling? could you not be knurling? could he not be knurling? could we not be knurling? could you not be knurling? could they not be knurling?
Perfect	V-ing perfect
could I not have knurled? could you not have knurled? could he not have knurled? could we not have knurled? could you not have knurled? could they not have knurled?	could I not have been knurling? could you not have been knurling? could he not have been knurling? could we not have been knurling? could you not have been knurling? could they not have been knurling?