English verb conjugation
COULD CRUMBLE

Regular verb: crumble - crumbled - crumbled

Affirmation

Simple form	V-ing form
I could crumble you could crumble she could crumble we could crumble you could crumble they could crumble	I could be crumbling you could be crumbling she could be crumbling we could be crumbling you could be crumbling they could be crumbling
Perfect	V-ing perfect
I could have crumbled you could have crumbled she could have crumbled we could have crumbled you could have crumbled they could have crumbled	I could have been crumbling you could have been crumbling she could have been crumbling we could have been crumbling you could have been crumbling they could have been crumbling

Negation

Simple form	V-ing form
I could not crumble you could not crumble she could not crumble we could not crumble you could not crumble they could not crumble	I could not be crumbling you could not be crumbling she could not be crumbling we could not be crumbling you could not be crumbling they could not be crumbling
Perfect	V-ing perfect
I could not have crumbled you could not have crumbled she could not have crumbled we could not have crumbled you could not have crumbled they could not have crumbled	I could not have been crumbling you could not have been crumbling she could not have been crumbling we could not have been crumbling you could not have been crumbling they could not have been crumbling

Interrogative form

Simple form	V-ing form
could I crumble? could you crumble? could she crumble? could we crumble? could you crumble? could they crumble?	could I be crumbling? could you be crumbling? could she be crumbling? could we be crumbling? could you be crumbling? could they be crumbling?
Perfect	V-ing perfect
could I have crumbled? could you have crumbled? could she have crumbled? could we have crumbled? could you have crumbled? could they have crumbled?	could I have been crumbling? could you have been crumbling? could she have been crumbling? could we have been crumbling? could you have been crumbling? could they have been crumbling?

Interro-negative form

Simple form	V-ing form
could I not crumble? could you not crumble? could she not crumble? could we not crumble? could you not crumble? could they not crumble?	could I not be crumbling? could you not be crumbling? could she not be crumbling? could we not be crumbling? could you not be crumbling? could they not be crumbling?
Perfect	V-ing perfect
could I not have crumbled? could you not have crumbled? could she not have crumbled? could we not have crumbled? could you not have crumbled? could they not have crumbled?	could I not have been crumbling? could you not have been crumbling? could she not have been crumbling? could we not have been crumbling? could you not have been crumbling? could they not have been crumbling?