phrases which are not necessary in these sentences. Not all sentences contain unnecessary phrases. a) My wallet has been stolen by someone. b) We were taught by a different teacher yesterday. c) Nick was operated on at the hospital by a doctor. d) The meal was served by a waiter in a red coat. e) We were shown round the museum by a guide. f) Two letters were delivered this morning by the postman. g) Three men have been arrested by the police. h) Yesterday a window was broken by someone.