I must post you must post she must post we must post you must post they must post
V-ing form
I must be posting you must be posting she must be posting we must be posting you must be posting they must be posting
Perfect
I must have posted you must have posted she must have posted we must have posted you must have posted they must have posted
V-ing perfect
I must have been posting you must have been posting she must have been posting we must have been posting you must have been posting they must have been posting
Negation
Simple form
I must not post you must not post she must not post we must not post you must not post they must not post
V-ing form
I must not be posting you must not be posting she must not be posting we must not be posting you must not be posting they must not be posting
Perfect
I must not have posted you must not have posted she must not have posted we must not have posted you must not have posted they must not have posted
V-ing perfect
I must not have been posting you must not have been posting she must not have been posting we must not have been posting you must not have been posting they must not have been posting
Interrogative form
Simple form
must I post? must you post? must she post? must we post? must you post? must they post?
V-ing form
must I be posting? must you be posting? must she be posting? must we be posting? must you be posting? must they be posting?
Perfect
must I have posted? must you have posted? must she have posted? must we have posted? must you have posted? must they have posted?
V-ing perfect
must I have been posting? must you have been posting? must she have been posting? must we have been posting? must you have been posting? must they have been posting?
Interro-negative form
Simple form
must I not post? must you not post? must she not post? must we not post? must you not post? must they not post?
V-ing form
must I not be posting? must you not be posting? must she not be posting? must we not be posting? must you not be posting? must they not be posting?
Perfect
must I not have posted? must you not have posted? must she not have posted? must we not have posted? must you not have posted? must they not have posted?
V-ing perfect
must I not have been posting? must you not have been posting? must she not have been posting? must we not have been posting? must you not have been posting? must they not have been posting?