From Longman Dictionary of Contemporary Englishbe to do somethingbe to do somethingformal a) used to talk about arrangements for the future Audrey and Jimmy are to be married in June. Two men are to appear in court on charges of armed robbery. b) TELL/ORDER somebody TO DO somethingused to give an order or to tell someone about a rule You are to wait here in this room until I return. All staff are to wear uniforms. c) used to say or ask what someone should do or what should happen What am I to tell her? He is not to be blamed. d) used to ask how something can be done How are we to get out of the present mess? → be
