English verb conjugation
COULD RUMBLE

Regular verb: rumble - rumbled - rumbled

Affirmation

Simple form	V-ing form
I could rumble you could rumble he could rumble we could rumble you could rumble they could rumble	I could be rumbling you could be rumbling he could be rumbling we could be rumbling you could be rumbling they could be rumbling
Perfect	V-ing perfect
I could have rumbled you could have rumbled he could have rumbled we could have rumbled you could have rumbled they could have rumbled	I could have been rumbling you could have been rumbling he could have been rumbling we could have been rumbling you could have been rumbling they could have been rumbling

Negation

Simple form	V-ing form
I could not rumble you could not rumble he could not rumble we could not rumble you could not rumble they could not rumble	I could not be rumbling you could not be rumbling he could not be rumbling we could not be rumbling you could not be rumbling they could not be rumbling
Perfect	V-ing perfect
I could not have rumbled you could not have rumbled he could not have rumbled we could not have rumbled you could not have rumbled they could not have rumbled	I could not have been rumbling you could not have been rumbling he could not have been rumbling we could not have been rumbling you could not have been rumbling they could not have been rumbling

Interrogative form

Simple form	V-ing form
could I rumble? could you rumble? could he rumble? could we rumble? could you rumble? could they rumble?	could I be rumbling? could you be rumbling? could he be rumbling? could we be rumbling? could you be rumbling? could they be rumbling?
Perfect	V-ing perfect
could I have rumbled? could you have rumbled? could he have rumbled? could we have rumbled? could you have rumbled? could they have rumbled?	could I have been rumbling? could you have been rumbling? could he have been rumbling? could we have been rumbling? could you have been rumbling? could they have been rumbling?

Interro-negative form

Simple form	V-ing form
could I not rumble? could you not rumble? could he not rumble? could we not rumble? could you not rumble? could they not rumble?	could I not be rumbling? could you not be rumbling? could he not be rumbling? could we not be rumbling? could you not be rumbling? could they not be rumbling?
Perfect	V-ing perfect
could I not have rumbled? could you not have rumbled? could he not have rumbled? could we not have rumbled? could you not have rumbled? could they not have rumbled?	could I not have been rumbling? could you not have been rumbling? could he not have been rumbling? could we not have been rumbling? could you not have been rumbling? could they not have been rumbling?