I must dumbfound you must dumbfound he must dumbfound we must dumbfound you must dumbfound they must dumbfound
V-ing form
I must be dumbfounding you must be dumbfounding he must be dumbfounding we must be dumbfounding you must be dumbfounding they must be dumbfounding
Perfect
I must have dumbfounded you must have dumbfounded he must have dumbfounded we must have dumbfounded you must have dumbfounded they must have dumbfounded
V-ing perfect
I must have been dumbfounding you must have been dumbfounding he must have been dumbfounding we must have been dumbfounding you must have been dumbfounding they must have been dumbfounding
Negation
Simple form
I mustn't dumbfound you mustn't dumbfound he mustn't dumbfound we mustn't dumbfound you mustn't dumbfound they mustn't dumbfound
V-ing form
I mustn't be dumbfounding you mustn't be dumbfounding he mustn't be dumbfounding we mustn't be dumbfounding you mustn't be dumbfounding they mustn't be dumbfounding
Perfect
I mustn't have dumbfounded you mustn't have dumbfounded he mustn't have dumbfounded we mustn't have dumbfounded you mustn't have dumbfounded they mustn't have dumbfounded
V-ing perfect
I mustn't have been dumbfounding you mustn't have been dumbfounding he mustn't have been dumbfounding we mustn't have been dumbfounding you mustn't have been dumbfounding they mustn't have been dumbfounding
Interrogative form
Simple form
must I dumbfound? must you dumbfound? must he dumbfound? must we dumbfound? must you dumbfound? must they dumbfound?
V-ing form
must I be dumbfounding? must you be dumbfounding? must he be dumbfounding? must we be dumbfounding? must you be dumbfounding? must they be dumbfounding?
Perfect
must I have dumbfounded? must you have dumbfounded? must he have dumbfounded? must we have dumbfounded? must you have dumbfounded? must they have dumbfounded?
V-ing perfect
must I have been dumbfounding? must you have been dumbfounding? must he have been dumbfounding? must we have been dumbfounding? must you have been dumbfounding? must they have been dumbfounding?
Interro-negative form
Simple form
mustn't I dumbfound? mustn't you dumbfound? mustn't he dumbfound? mustn't we dumbfound? mustn't you dumbfound? mustn't they dumbfound?
V-ing form
mustn't I be dumbfounding? mustn't you be dumbfounding? mustn't he be dumbfounding? mustn't we be dumbfounding? mustn't you be dumbfounding? mustn't they be dumbfounding?
Perfect
mustn't I have dumbfounded? mustn't you have dumbfounded? mustn't he have dumbfounded? mustn't we have dumbfounded? mustn't you have dumbfounded? mustn't they have dumbfounded?
V-ing perfect
mustn't I have been dumbfounding? mustn't you have been dumbfounding? mustn't he have been dumbfounding? mustn't we have been dumbfounding? mustn't you have been dumbfounding? mustn't they have been dumbfounding?