I must balloon you must balloon she must balloon we must balloon you must balloon they must balloon
V-ing form
I must be ballooning you must be ballooning she must be ballooning we must be ballooning you must be ballooning they must be ballooning
Perfect
I must have ballooned you must have ballooned she must have ballooned we must have ballooned you must have ballooned they must have ballooned
V-ing perfect
I must have been ballooning you must have been ballooning she must have been ballooning we must have been ballooning you must have been ballooning they must have been ballooning
Negation
Simple form
I must not balloon you must not balloon she must not balloon we must not balloon you must not balloon they must not balloon
V-ing form
I must not be ballooning you must not be ballooning she must not be ballooning we must not be ballooning you must not be ballooning they must not be ballooning
Perfect
I must not have ballooned you must not have ballooned she must not have ballooned we must not have ballooned you must not have ballooned they must not have ballooned
V-ing perfect
I must not have been ballooning you must not have been ballooning she must not have been ballooning we must not have been ballooning you must not have been ballooning they must not have been ballooning
Interrogative form
Simple form
must I balloon? must you balloon? must she balloon? must we balloon? must you balloon? must they balloon?
V-ing form
must I be ballooning? must you be ballooning? must she be ballooning? must we be ballooning? must you be ballooning? must they be ballooning?
Perfect
must I have ballooned? must you have ballooned? must she have ballooned? must we have ballooned? must you have ballooned? must they have ballooned?
V-ing perfect
must I have been ballooning? must you have been ballooning? must she have been ballooning? must we have been ballooning? must you have been ballooning? must they have been ballooning?
Interro-negative form
Simple form
must I not balloon? must you not balloon? must she not balloon? must we not balloon? must you not balloon? must they not balloon?
V-ing form
must I not be ballooning? must you not be ballooning? must she not be ballooning? must we not be ballooning? must you not be ballooning? must they not be ballooning?
Perfect
must I not have ballooned? must you not have ballooned? must she not have ballooned? must we not have ballooned? must you not have ballooned? must they not have ballooned?
V-ing perfect
must I not have been ballooning? must you not have been ballooning? must she not have been ballooning? must we not have been ballooning? must you not have been ballooning? must they not have been ballooning?