I must flag you must flag she must flag we must flag you must flag they must flag
V-ing form
I must be flagging you must be flagging she must be flagging we must be flagging you must be flagging they must be flagging
Perfect
I must have flagged you must have flagged she must have flagged we must have flagged you must have flagged they must have flagged
V-ing perfect
I must have been flagging you must have been flagging she must have been flagging we must have been flagging you must have been flagging they must have been flagging
Negation
Simple form
I must not flag you must not flag she must not flag we must not flag you must not flag they must not flag
V-ing form
I must not be flagging you must not be flagging she must not be flagging we must not be flagging you must not be flagging they must not be flagging
Perfect
I must not have flagged you must not have flagged she must not have flagged we must not have flagged you must not have flagged they must not have flagged
V-ing perfect
I must not have been flagging you must not have been flagging she must not have been flagging we must not have been flagging you must not have been flagging they must not have been flagging
Interrogative form
Simple form
must I flag? must you flag? must she flag? must we flag? must you flag? must they flag?
V-ing form
must I be flagging? must you be flagging? must she be flagging? must we be flagging? must you be flagging? must they be flagging?
Perfect
must I have flagged? must you have flagged? must she have flagged? must we have flagged? must you have flagged? must they have flagged?
V-ing perfect
must I have been flagging? must you have been flagging? must she have been flagging? must we have been flagging? must you have been flagging? must they have been flagging?
Interro-negative form
Simple form
must I not flag? must you not flag? must she not flag? must we not flag? must you not flag? must they not flag?
V-ing form
must I not be flagging? must you not be flagging? must she not be flagging? must we not be flagging? must you not be flagging? must they not be flagging?
Perfect
must I not have flagged? must you not have flagged? must she not have flagged? must we not have flagged? must you not have flagged? must they not have flagged?
V-ing perfect
must I not have been flagging? must you not have been flagging? must she not have been flagging? must we not have been flagging? must you not have been flagging? must they not have been flagging?