English verb conjugation
COULD DUMB

Regular verb: dumb - dumbed - dumbed

Affirmation

Simple form	V-ing form
I could dumb you could dumb she could dumb we could dumb you could dumb they could dumb	I could be dumbing you could be dumbing she could be dumbing we could be dumbing you could be dumbing they could be dumbing
Perfect	V-ing perfect
I could have dumbed you could have dumbed she could have dumbed we could have dumbed you could have dumbed they could have dumbed	I could have been dumbing you could have been dumbing she could have been dumbing we could have been dumbing you could have been dumbing they could have been dumbing

Negation

Simple form	V-ing form
I could not dumb you could not dumb she could not dumb we could not dumb you could not dumb they could not dumb	I could not be dumbing you could not be dumbing she could not be dumbing we could not be dumbing you could not be dumbing they could not be dumbing
Perfect	V-ing perfect
I could not have dumbed you could not have dumbed she could not have dumbed we could not have dumbed you could not have dumbed they could not have dumbed	I could not have been dumbing you could not have been dumbing she could not have been dumbing we could not have been dumbing you could not have been dumbing they could not have been dumbing

Interrogative form

Simple form	V-ing form
could I dumb? could you dumb? could she dumb? could we dumb? could you dumb? could they dumb?	could I be dumbing? could you be dumbing? could she be dumbing? could we be dumbing? could you be dumbing? could they be dumbing?
Perfect	V-ing perfect
could I have dumbed? could you have dumbed? could she have dumbed? could we have dumbed? could you have dumbed? could they have dumbed?	could I have been dumbing? could you have been dumbing? could she have been dumbing? could we have been dumbing? could you have been dumbing? could they have been dumbing?

Interro-negative form

Simple form	V-ing form
could I not dumb? could you not dumb? could she not dumb? could we not dumb? could you not dumb? could they not dumb?	could I not be dumbing? could you not be dumbing? could she not be dumbing? could we not be dumbing? could you not be dumbing? could they not be dumbing?
Perfect	V-ing perfect
could I not have dumbed? could you not have dumbed? could she not have dumbed? could we not have dumbed? could you not have dumbed? could they not have dumbed?	could I not have been dumbing? could you not have been dumbing? could she not have been dumbing? could we not have been dumbing? could you not have been dumbing? could they not have been dumbing?