I must lesson you must lesson she must lesson we must lesson you must lesson they must lesson
V-ing form
I must be lessoning you must be lessoning she must be lessoning we must be lessoning you must be lessoning they must be lessoning
Perfect
I must have lessoned you must have lessoned she must have lessoned we must have lessoned you must have lessoned they must have lessoned
V-ing perfect
I must have been lessoning you must have been lessoning she must have been lessoning we must have been lessoning you must have been lessoning they must have been lessoning
Negation
Simple form
I mustn't lesson you mustn't lesson she mustn't lesson we mustn't lesson you mustn't lesson they mustn't lesson
V-ing form
I mustn't be lessoning you mustn't be lessoning she mustn't be lessoning we mustn't be lessoning you mustn't be lessoning they mustn't be lessoning
Perfect
I mustn't have lessoned you mustn't have lessoned she mustn't have lessoned we mustn't have lessoned you mustn't have lessoned they mustn't have lessoned
V-ing perfect
I mustn't have been lessoning you mustn't have been lessoning she mustn't have been lessoning we mustn't have been lessoning you mustn't have been lessoning they mustn't have been lessoning
Interrogative form
Simple form
must I lesson? must you lesson? must she lesson? must we lesson? must you lesson? must they lesson?
V-ing form
must I be lessoning? must you be lessoning? must she be lessoning? must we be lessoning? must you be lessoning? must they be lessoning?
Perfect
must I have lessoned? must you have lessoned? must she have lessoned? must we have lessoned? must you have lessoned? must they have lessoned?
V-ing perfect
must I have been lessoning? must you have been lessoning? must she have been lessoning? must we have been lessoning? must you have been lessoning? must they have been lessoning?
Interro-negative form
Simple form
mustn't I lesson? mustn't you lesson? mustn't she lesson? mustn't we lesson? mustn't you lesson? mustn't they lesson?
V-ing form
mustn't I be lessoning? mustn't you be lessoning? mustn't she be lessoning? mustn't we be lessoning? mustn't you be lessoning? mustn't they be lessoning?
Perfect
mustn't I have lessoned? mustn't you have lessoned? mustn't she have lessoned? mustn't we have lessoned? mustn't you have lessoned? mustn't they have lessoned?
V-ing perfect
mustn't I have been lessoning? mustn't you have been lessoning? mustn't she have been lessoning? mustn't we have been lessoning? mustn't you have been lessoning? mustn't they have been lessoning?