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