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 couldn't dumb you couldn't dumb she couldn't dumb we couldn't dumb you couldn't dumb they couldn't dumb	I couldn't be dumbing you couldn't be dumbing she couldn't be dumbing we couldn't be dumbing you couldn't be dumbing they couldn't be dumbing
Perfect	V-ing perfect
I couldn't have dumbed you couldn't have dumbed she couldn't have dumbed we couldn't have dumbed you couldn't have dumbed they couldn't have dumbed	I couldn't have been dumbing you couldn't have been dumbing she couldn't have been dumbing we couldn't have been dumbing you couldn't have been dumbing they couldn't 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
couldn't I dumb? couldn't you dumb? couldn't she dumb? couldn't we dumb? couldn't you dumb? couldn't they dumb?	couldn't I be dumbing? couldn't you be dumbing? couldn't she be dumbing? couldn't we be dumbing? couldn't you be dumbing? couldn't they be dumbing?
Perfect	V-ing perfect
couldn't I have dumbed? couldn't you have dumbed? couldn't she have dumbed? couldn't we have dumbed? couldn't you have dumbed? couldn't they have dumbed?	couldn't I have been dumbing? couldn't you have been dumbing? couldn't she have been dumbing? couldn't we have been dumbing? couldn't you have been dumbing? couldn't they have been dumbing?