I must add you must add he must add we must add you must add they must add
V-ing form
I must be adding you must be adding he must be adding we must be adding you must be adding they must be adding
Perfect
I must have added you must have added he must have added we must have added you must have added they must have added
V-ing perfect
I must have been adding you must have been adding he must have been adding we must have been adding you must have been adding they must have been adding
Negation
Simple form
I must not add you must not add he must not add we must not add you must not add they must not add
V-ing form
I must not be adding you must not be adding he must not be adding we must not be adding you must not be adding they must not be adding
Perfect
I must not have added you must not have added he must not have added we must not have added you must not have added they must not have added
V-ing perfect
I must not have been adding you must not have been adding he must not have been adding we must not have been adding you must not have been adding they must not have been adding
Interrogative form
Simple form
must I add? must you add? must he add? must we add? must you add? must they add?
V-ing form
must I be adding? must you be adding? must he be adding? must we be adding? must you be adding? must they be adding?
Perfect
must I have added? must you have added? must he have added? must we have added? must you have added? must they have added?
V-ing perfect
must I have been adding? must you have been adding? must he have been adding? must we have been adding? must you have been adding? must they have been adding?
Interro-negative form
Simple form
must I not add? must you not add? must he not add? must we not add? must you not add? must they not add?
V-ing form
must I not be adding? must you not be adding? must he not be adding? must we not be adding? must you not be adding? must they not be adding?
Perfect
must I not have added? must you not have added? must he not have added? must we not have added? must you not have added? must they not have added?
V-ing perfect
must I not have been adding? must you not have been adding? must he not have been adding? must we not have been adding? must you not have been adding? must they not have been adding?