the business letter is the principal means used by a business firm to keep in touch with its customers; often enough it is the only one and customers form their impressions of the firm from the tone and quality of the letters it sends out.

　　business does not call for the elegant language of the poet, but it does require us to express ourselves accurately in plain language secret of good business letter writing is to write simply, in an easy and natural way----like one friendly human being talking to another.

　　in other words, try to make your letters sound as much as possible like good conversation.