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