I must lie you must lie she must lie we must lie you must lie they must lie
V-ing form
I must be lying you must be lying she must be lying we must be lying you must be lying they must be lying
Perfect
I must have lain you must have lain she 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 she must have been lying we must have been lying you must have been lying they must have been lying
Negation
Simple form
I must not lie you must not lie she must not lie we must not lie you must not lie they must not lie
V-ing form
I must not be lying you must not be lying she must not be lying we must not be lying you must not be lying they must not be lying
Perfect
I must not have lain you must not have lain she must not have lain we must not have lain you must not have lain they must not have lain
V-ing perfect
I must not have been lying you must not have been lying she must not have been lying we must not have been lying you must not have been lying they must not have been lying
Interrogative form
Simple form
must I lie? must you lie? must she lie? must we lie? must you lie? must they lie?
V-ing form
must I be lying? must you be lying? must she be lying? must we be lying? must you be lying? must they be lying?
Perfect
must I have lain? must you have lain? must she 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 she have been lying? must we have been lying? must you have been lying? must they have been lying?
Interro-negative form
Simple form
must I not lie? must you not lie? must she not lie? must we not lie? must you not lie? must they not lie?
V-ing form
must I not be lying? must you not be lying? must she not be lying? must we not be lying? must you not be lying? must they not be lying?
Perfect
must I not have lain? must you not have lain? must she not have lain? must we not have lain? must you not have lain? must they not have lain?
V-ing perfect
must I not have been lying? must you not have been lying? must she not have been lying? must we not have been lying? must you not have been lying? must they not have been lying?