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