I must bark you must bark she must bark we must bark you must bark they must bark
V-ing form
I must be barking you must be barking she must be barking we must be barking you must be barking they must be barking
Perfect
I must have barked you must have barked she must have barked we must have barked you must have barked they must have barked
V-ing perfect
I must have been barking you must have been barking she must have been barking we must have been barking you must have been barking they must have been barking
Negation
Simple form
I mustn't bark you mustn't bark she mustn't bark we mustn't bark you mustn't bark they mustn't bark
V-ing form
I mustn't be barking you mustn't be barking she mustn't be barking we mustn't be barking you mustn't be barking they mustn't be barking
Perfect
I mustn't have barked you mustn't have barked she mustn't have barked we mustn't have barked you mustn't have barked they mustn't have barked
V-ing perfect
I mustn't have been barking you mustn't have been barking she mustn't have been barking we mustn't have been barking you mustn't have been barking they mustn't have been barking
Interrogative form
Simple form
must I bark? must you bark? must she bark? must we bark? must you bark? must they bark?
V-ing form
must I be barking? must you be barking? must she be barking? must we be barking? must you be barking? must they be barking?
Perfect
must I have barked? must you have barked? must she have barked? must we have barked? must you have barked? must they have barked?
V-ing perfect
must I have been barking? must you have been barking? must she have been barking? must we have been barking? must you have been barking? must they have been barking?
Interro-negative form
Simple form
mustn't I bark? mustn't you bark? mustn't she bark? mustn't we bark? mustn't you bark? mustn't they bark?
V-ing form
mustn't I be barking? mustn't you be barking? mustn't she be barking? mustn't we be barking? mustn't you be barking? mustn't they be barking?
Perfect
mustn't I have barked? mustn't you have barked? mustn't she have barked? mustn't we have barked? mustn't you have barked? mustn't they have barked?
V-ing perfect
mustn't I have been barking? mustn't you have been barking? mustn't she have been barking? mustn't we have been barking? mustn't you have been barking? mustn't they have been barking?