I must pay you must pay she must pay we must pay you must pay they must pay
V-ing form
I must be paying you must be paying she must be paying we must be paying you must be paying they must be paying
Perfect
I must have paid you must have paid she must have paid we must have paid you must have paid they must have paid
V-ing perfect
I must have been paying you must have been paying she must have been paying we must have been paying you must have been paying they must have been paying
Negation
Simple form
I must not pay you must not pay she must not pay we must not pay you must not pay they must not pay
V-ing form
I must not be paying you must not be paying she must not be paying we must not be paying you must not be paying they must not be paying
Perfect
I must not have paid you must not have paid she must not have paid we must not have paid you must not have paid they must not have paid
V-ing perfect
I must not have been paying you must not have been paying she must not have been paying we must not have been paying you must not have been paying they must not have been paying
Interrogative form
Simple form
must I pay? must you pay? must she pay? must we pay? must you pay? must they pay?
V-ing form
must I be paying? must you be paying? must she be paying? must we be paying? must you be paying? must they be paying?
Perfect
must I have paid? must you have paid? must she have paid? must we have paid? must you have paid? must they have paid?
V-ing perfect
must I have been paying? must you have been paying? must she have been paying? must we have been paying? must you have been paying? must they have been paying?
Interro-negative form
Simple form
must I not pay? must you not pay? must she not pay? must we not pay? must you not pay? must they not pay?
V-ing form
must I not be paying? must you not be paying? must she not be paying? must we not be paying? must you not be paying? must they not be paying?
Perfect
must I not have paid? must you not have paid? must she not have paid? must we not have paid? must you not have paid? must they not have paid?
V-ing perfect
must I not have been paying? must you not have been paying? must she not have been paying? must we not have been paying? must you not have been paying? must they not have been paying?