I must turn you must turn he must turn we must turn you must turn they must turn
V-ing form
I must be turning you must be turning he must be turning we must be turning you must be turning they must be turning
Perfect
I must have turned you must have turned he must have turned we must have turned you must have turned they must have turned
V-ing perfect
I must have been turning you must have been turning he must have been turning we must have been turning you must have been turning they must have been turning
Negation
Simple form
I must not turn you must not turn he must not turn we must not turn you must not turn they must not turn
V-ing form
I must not be turning you must not be turning he must not be turning we must not be turning you must not be turning they must not be turning
Perfect
I must not have turned you must not have turned he must not have turned we must not have turned you must not have turned they must not have turned
V-ing perfect
I must not have been turning you must not have been turning he must not have been turning we must not have been turning you must not have been turning they must not have been turning
Interrogative form
Simple form
must I turn? must you turn? must he turn? must we turn? must you turn? must they turn?
V-ing form
must I be turning? must you be turning? must he be turning? must we be turning? must you be turning? must they be turning?
Perfect
must I have turned? must you have turned? must he have turned? must we have turned? must you have turned? must they have turned?
V-ing perfect
must I have been turning? must you have been turning? must he have been turning? must we have been turning? must you have been turning? must they have been turning?
Interro-negative form
Simple form
must I not turn? must you not turn? must he not turn? must we not turn? must you not turn? must they not turn?
V-ing form
must I not be turning? must you not be turning? must he not be turning? must we not be turning? must you not be turning? must they not be turning?
Perfect
must I not have turned? must you not have turned? must he not have turned? must we not have turned? must you not have turned? must they not have turned?
V-ing perfect
must I not have been turning? must you not have been turning? must he not have been turning? must we not have been turning? must you not have been turning? must they not have been turning?