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