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