I must authorise you must authorise he must authorise we must authorise you must authorise they must authorise
V-ing form
I must be authorising you must be authorising he must be authorising we must be authorising you must be authorising they must be authorising
Perfect
I must have authorised you must have authorised he must have authorised we must have authorised you must have authorised they must have authorised
V-ing perfect
I must have been authorising you must have been authorising he must have been authorising we must have been authorising you must have been authorising they must have been authorising
Negation
Simple form
I must not authorise you must not authorise he must not authorise we must not authorise you must not authorise they must not authorise
V-ing form
I must not be authorising you must not be authorising he must not be authorising we must not be authorising you must not be authorising they must not be authorising
Perfect
I must not have authorised you must not have authorised he must not have authorised we must not have authorised you must not have authorised they must not have authorised
V-ing perfect
I must not have been authorising you must not have been authorising he must not have been authorising we must not have been authorising you must not have been authorising they must not have been authorising
Interrogative form
Simple form
must I authorise? must you authorise? must he authorise? must we authorise? must you authorise? must they authorise?
V-ing form
must I be authorising? must you be authorising? must he be authorising? must we be authorising? must you be authorising? must they be authorising?
Perfect
must I have authorised? must you have authorised? must he have authorised? must we have authorised? must you have authorised? must they have authorised?
V-ing perfect
must I have been authorising? must you have been authorising? must he have been authorising? must we have been authorising? must you have been authorising? must they have been authorising?
Interro-negative form
Simple form
must I not authorise? must you not authorise? must he not authorise? must we not authorise? must you not authorise? must they not authorise?
V-ing form
must I not be authorising? must you not be authorising? must he not be authorising? must we not be authorising? must you not be authorising? must they not be authorising?
Perfect
must I not have authorised? must you not have authorised? must he not have authorised? must we not have authorised? must you not have authorised? must they not have authorised?
V-ing perfect
must I not have been authorising? must you not have been authorising? must he not have been authorising? must we not have been authorising? must you not have been authorising? must they not have been authorising?