I must itch you must itch he must itch we must itch you must itch they must itch
V-ing form
I must be itching you must be itching he must be itching we must be itching you must be itching they must be itching
Perfect
I must have itched you must have itched he must have itched we must have itched you must have itched they must have itched
V-ing perfect
I must have been itching you must have been itching he must have been itching we must have been itching you must have been itching they must have been itching
Negation
Simple form
I must not itch you must not itch he must not itch we must not itch you must not itch they must not itch
V-ing form
I must not be itching you must not be itching he must not be itching we must not be itching you must not be itching they must not be itching
Perfect
I must not have itched you must not have itched he must not have itched we must not have itched you must not have itched they must not have itched
V-ing perfect
I must not have been itching you must not have been itching he must not have been itching we must not have been itching you must not have been itching they must not have been itching
Interrogative form
Simple form
must I itch? must you itch? must he itch? must we itch? must you itch? must they itch?
V-ing form
must I be itching? must you be itching? must he be itching? must we be itching? must you be itching? must they be itching?
Perfect
must I have itched? must you have itched? must he have itched? must we have itched? must you have itched? must they have itched?
V-ing perfect
must I have been itching? must you have been itching? must he have been itching? must we have been itching? must you have been itching? must they have been itching?
Interro-negative form
Simple form
must I not itch? must you not itch? must he not itch? must we not itch? must you not itch? must they not itch?
V-ing form
must I not be itching? must you not be itching? must he not be itching? must we not be itching? must you not be itching? must they not be itching?
Perfect
must I not have itched? must you not have itched? must he not have itched? must we not have itched? must you not have itched? must they not have itched?
V-ing perfect
must I not have been itching? must you not have been itching? must he not have been itching? must we not have been itching? must you not have been itching? must they not have been itching?