English verb conjugation
CAN DUMB

Regular verb: dumb - dumbed - dumbed

Affirmation

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

Negation

Simple form	V-ing form
I cannot dumb you cannot dumb he cannot dumb we cannot dumb you cannot dumb they cannot dumb	I cannot be dumbing you cannot be dumbing he cannot be dumbing we cannot be dumbing you cannot be dumbing they cannot be dumbing
Perfect	V-ing perfect
I cannot have dumbed you cannot have dumbed he cannot have dumbed we cannot have dumbed you cannot have dumbed they cannot have dumbed	I cannot have been dumbing you cannot have been dumbing he cannot have been dumbing we cannot have been dumbing you cannot have been dumbing they cannot have been dumbing

Interrogative form

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

Interro-negative form

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