I must fart you must fart she must fart we must fart you must fart they must fart
V-ing form
I must be farting you must be farting she must be farting we must be farting you must be farting they must be farting
Perfect
I must have farted you must have farted she 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 she 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 she 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 she 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 she 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 she 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 she fart? must we fart? must you fart? must they fart?
V-ing form
must I be farting? must you be farting? must she be farting? must we be farting? must you be farting? must they be farting?
Perfect
must I have farted? must you have farted? must she 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 she 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 she 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 she 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 she 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 she have been farting? mustn't we have been farting? mustn't you have been farting? mustn't they have been farting?