could dumbfound
Regular verb: dumbfound - dumbfounded- dumbfounded

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could dumbfound
you could dumbfound
she could dumbfound
we could dumbfound
you could dumbfound
they could dumbfound 	I could be dumbfounding
you could be dumbfounding
she could be dumbfounding
we could be dumbfounding
you could be dumbfounding
they could be dumbfounding	I could have dumbfounded
you could have dumbfounded
she could have dumbfounded
we could have dumbfounded
you could have dumbfounded
they could have dumbfounded	I could have been dumbfounding
you could have been dumbfounding
she could have been dumbfounding
we could have been dumbfounding
you could have been dumbfounding
they could have been dumbfounding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not dumbfound
you could not dumbfound
she could not dumbfound
we could not dumbfound
you could not dumbfound
they could not dumbfound 	I could not be dumbfounding
you could not be dumbfounding
she could not be dumbfounding
we could not be dumbfounding
you could not be dumbfounding
they could not be dumbfounding	I could not have dumbfounded
you could not have dumbfounded
she could not have dumbfounded
we could not have dumbfounded
you could not have dumbfounded
they could not have dumbfounded	I could not have been dumbfounding
you could not have been dumbfounding
she could not have been dumbfounding
we could not have been dumbfounding
you could not have been dumbfounding
they could not have been dumbfounding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I dumbfound?
could you dumbfound?
could she dumbfound?
could we dumbfound?
could you dumbfound?
could they dumbfound? 	could I be dumbfounding?
could you be dumbfounding?
could she be dumbfounding?
could we be dumbfounding?
could you be dumbfounding?
could they be dumbfounding? 	could I have dumbfounded?
could you have dumbfounded?
could she have dumbfounded?
could we have dumbfounded?
could you have dumbfounded?
could they have dumbfounded? 	could I have been dumbfounding?
could you have been dumbfounding?
could she have been dumbfounding?
could we have been dumbfounding?
could you have been dumbfounding?
could they have been dumbfounding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not dumbfound?
could you not dumbfound?
could she not dumbfound?
could we not dumbfound?
could you not dumbfound?
could they not dumbfound? 	could I not be dumbfounding?
could you not be dumbfounding?
could she not be dumbfounding?
could we not be dumbfounding?
could you not be dumbfounding?
could they not be dumbfounding? 	could I not have dumbfounded?
could you not have dumbfounded?
could she not have dumbfounded?
could we not have dumbfounded?
could you not have dumbfounded?
could they not have dumbfounded? 	could I not have been dumbfounding?
could you not have been dumbfounding?
could she not have been dumbfounding?
could we not have been dumbfounding?
could you not have been dumbfounding?
could they not have been dumbfounding?