English verb conjugation
COULD CURB

Regular verb: curb - curbed - curbed

Affirmation

Simple form	V-ing form
I could curb you could curb he could curb we could curb you could curb they could curb	I could be curbing you could be curbing he could be curbing we could be curbing you could be curbing they could be curbing
Perfect	V-ing perfect
I could have curbed you could have curbed he could have curbed we could have curbed you could have curbed they could have curbed	I could have been curbing you could have been curbing he could have been curbing we could have been curbing you could have been curbing they could have been curbing

Negation

Simple form	V-ing form
I could not curb you could not curb he could not curb we could not curb you could not curb they could not curb	I could not be curbing you could not be curbing he could not be curbing we could not be curbing you could not be curbing they could not be curbing
Perfect	V-ing perfect
I could not have curbed you could not have curbed he could not have curbed we could not have curbed you could not have curbed they could not have curbed	I could not have been curbing you could not have been curbing he could not have been curbing we could not have been curbing you could not have been curbing they could not have been curbing

Interrogative form

Simple form	V-ing form
could I curb? could you curb? could he curb? could we curb? could you curb? could they curb?	could I be curbing? could you be curbing? could he be curbing? could we be curbing? could you be curbing? could they be curbing?
Perfect	V-ing perfect
could I have curbed? could you have curbed? could he have curbed? could we have curbed? could you have curbed? could they have curbed?	could I have been curbing? could you have been curbing? could he have been curbing? could we have been curbing? could you have been curbing? could they have been curbing?

Interro-negative form

Simple form	V-ing form
could I not curb? could you not curb? could he not curb? could we not curb? could you not curb? could they not curb?	could I not be curbing? could you not be curbing? could he not be curbing? could we not be curbing? could you not be curbing? could they not be curbing?
Perfect	V-ing perfect
could I not have curbed? could you not have curbed? could he not have curbed? could we not have curbed? could you not have curbed? could they not have curbed?	could I not have been curbing? could you not have been curbing? could he not have been curbing? could we not have been curbing? could you not have been curbing? could they not have been curbing?