English verb conjugation
COULD MUMBLE

Regular verb: mumble - mumbled - mumbled

Affirmation

Simple form	V-ing form
I could mumble you could mumble he could mumble we could mumble you could mumble they could mumble	I could be mumbling you could be mumbling he could be mumbling we could be mumbling you could be mumbling they could be mumbling
Perfect	V-ing perfect
I could have mumbled you could have mumbled he could have mumbled we could have mumbled you could have mumbled they could have mumbled	I could have been mumbling you could have been mumbling he could have been mumbling we could have been mumbling you could have been mumbling they could have been mumbling

Negation

Simple form	V-ing form
I could not mumble you could not mumble he could not mumble we could not mumble you could not mumble they could not mumble	I could not be mumbling you could not be mumbling he could not be mumbling we could not be mumbling you could not be mumbling they could not be mumbling
Perfect	V-ing perfect
I could not have mumbled you could not have mumbled he could not have mumbled we could not have mumbled you could not have mumbled they could not have mumbled	I could not have been mumbling you could not have been mumbling he could not have been mumbling we could not have been mumbling you could not have been mumbling they could not have been mumbling

Interrogative form

Simple form	V-ing form
could I mumble? could you mumble? could he mumble? could we mumble? could you mumble? could they mumble?	could I be mumbling? could you be mumbling? could he be mumbling? could we be mumbling? could you be mumbling? could they be mumbling?
Perfect	V-ing perfect
could I have mumbled? could you have mumbled? could he have mumbled? could we have mumbled? could you have mumbled? could they have mumbled?	could I have been mumbling? could you have been mumbling? could he have been mumbling? could we have been mumbling? could you have been mumbling? could they have been mumbling?

Interro-negative form

Simple form	V-ing form
could I not mumble? could you not mumble? could he not mumble? could we not mumble? could you not mumble? could they not mumble?	could I not be mumbling? could you not be mumbling? could he not be mumbling? could we not be mumbling? could you not be mumbling? could they not be mumbling?
Perfect	V-ing perfect
could I not have mumbled? could you not have mumbled? could he not have mumbled? could we not have mumbled? could you not have mumbled? could they not have mumbled?	could I not have been mumbling? could you not have been mumbling? could he not have been mumbling? could we not have been mumbling? could you not have been mumbling? could they not have been mumbling?