I must clutch you must clutch he must clutch we must clutch you must clutch they must clutch
V-ing form
I must be clutching you must be clutching he must be clutching we must be clutching you must be clutching they must be clutching
Perfect
I must have clutched you must have clutched he must have clutched we must have clutched you must have clutched they must have clutched
V-ing perfect
I must have been clutching you must have been clutching he must have been clutching we must have been clutching you must have been clutching they must have been clutching
Negation
Simple form
I must not clutch you must not clutch he must not clutch we must not clutch you must not clutch they must not clutch
V-ing form
I must not be clutching you must not be clutching he must not be clutching we must not be clutching you must not be clutching they must not be clutching
Perfect
I must not have clutched you must not have clutched he must not have clutched we must not have clutched you must not have clutched they must not have clutched
V-ing perfect
I must not have been clutching you must not have been clutching he must not have been clutching we must not have been clutching you must not have been clutching they must not have been clutching
Interrogative form
Simple form
must I clutch? must you clutch? must he clutch? must we clutch? must you clutch? must they clutch?
V-ing form
must I be clutching? must you be clutching? must he be clutching? must we be clutching? must you be clutching? must they be clutching?
Perfect
must I have clutched? must you have clutched? must he have clutched? must we have clutched? must you have clutched? must they have clutched?
V-ing perfect
must I have been clutching? must you have been clutching? must he have been clutching? must we have been clutching? must you have been clutching? must they have been clutching?
Interro-negative form
Simple form
must I not clutch? must you not clutch? must he not clutch? must we not clutch? must you not clutch? must they not clutch?
V-ing form
must I not be clutching? must you not be clutching? must he not be clutching? must we not be clutching? must you not be clutching? must they not be clutching?
Perfect
must I not have clutched? must you not have clutched? must he not have clutched? must we not have clutched? must you not have clutched? must they not have clutched?
V-ing perfect
must I not have been clutching? must you not have been clutching? must he not have been clutching? must we not have been clutching? must you not have been clutching? must they not have been clutching?