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