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 couldn't mumble you couldn't mumble he couldn't mumble we couldn't mumble you couldn't mumble they couldn't mumble	I couldn't be mumbling you couldn't be mumbling he couldn't be mumbling we couldn't be mumbling you couldn't be mumbling they couldn't be mumbling
Perfect	V-ing perfect
I couldn't have mumbled you couldn't have mumbled he couldn't have mumbled we couldn't have mumbled you couldn't have mumbled they couldn't have mumbled	I couldn't have been mumbling you couldn't have been mumbling he couldn't have been mumbling we couldn't have been mumbling you couldn't have been mumbling they couldn't 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
couldn't I mumble? couldn't you mumble? couldn't he mumble? couldn't we mumble? couldn't you mumble? couldn't they mumble?	couldn't I be mumbling? couldn't you be mumbling? couldn't he be mumbling? couldn't we be mumbling? couldn't you be mumbling? couldn't they be mumbling?
Perfect	V-ing perfect
couldn't I have mumbled? couldn't you have mumbled? couldn't he have mumbled? couldn't we have mumbled? couldn't you have mumbled? couldn't they have mumbled?	couldn't I have been mumbling? couldn't you have been mumbling? couldn't he have been mumbling? couldn't we have been mumbling? couldn't you have been mumbling? couldn't they have been mumbling?