One of six related documents, making up a U.S. Air Force correspondence course, this publication deals with effective writing and emphasizes the sentence as the basic unit of written communication. Part one focuses on internal sentence punctuation and covers the use of the comma, semicolon, colon, period, capital, abbreviations, and numbers. Part two emphasizes the basic sentence and its contribution to the communication process, and covers the parts of speech, sentence form and content, transitional devices between and within sentences, and the planning, organizing, and developing of a paragraph. A self-help test on effective writing and the answer key are included. (EL)