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