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