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