sincerely faithfully咩情况用呢?

1.Use 'Yours sincerely' when you know who you are writing to,-->You have greeted the recipient with his/her NAME.E.g.You have written:-Dear John,-Dear Miss Lee,2.Use 'Yours faithfully' when you have addressed the recipientas:-Dear Sir -Dear Madam -Dear Sir or Madam -To whom It may concern3.Use 'Best regards' when you are writing with a friendly tone or writing a personal letter or emails.Conclusion:Person you are writing to:/Complimentary close :Dear Kate / Yours sincerelyDear Ms.Wu / Yours sincerelyDear Sir or Madam / Yours faithfullyDear Parents/ Yours faithfully