I must haven you must haven he must haven we must haven you must haven they must haven
V-ing form
I must be havening you must be havening he must be havening we must be havening you must be havening they must be havening
Perfect
I must have havened you must have havened he must have havened we must have havened you must have havened they must have havened
V-ing perfect
I must have been havening you must have been havening he must have been havening we must have been havening you must have been havening they must have been havening
Negation
Simple form
I must not haven you must not haven he must not haven we must not haven you must not haven they must not haven
V-ing form
I must not be havening you must not be havening he must not be havening we must not be havening you must not be havening they must not be havening
Perfect
I must not have havened you must not have havened he must not have havened we must not have havened you must not have havened they must not have havened
V-ing perfect
I must not have been havening you must not have been havening he must not have been havening we must not have been havening you must not have been havening they must not have been havening
Interrogative form
Simple form
must I haven? must you haven? must he haven? must we haven? must you haven? must they haven?
V-ing form
must I be havening? must you be havening? must he be havening? must we be havening? must you be havening? must they be havening?
Perfect
must I have havened? must you have havened? must he have havened? must we have havened? must you have havened? must they have havened?
V-ing perfect
must I have been havening? must you have been havening? must he have been havening? must we have been havening? must you have been havening? must they have been havening?
Interro-negative form
Simple form
must I not haven? must you not haven? must he not haven? must we not haven? must you not haven? must they not haven?
V-ing form
must I not be havening? must you not be havening? must he not be havening? must we not be havening? must you not be havening? must they not be havening?
Perfect
must I not have havened? must you not have havened? must he not have havened? must we not have havened? must you not have havened? must they not have havened?
V-ing perfect
must I not have been havening? must you not have been havening? must he not have been havening? must we not have been havening? must you not have been havening? must they not have been havening?