Dear Nancy, how do you analyze a letter? Love, Trez. Dear Trez, you use a Letter Analysis Worksheet. Love, Nancy. This richly detailed instructional activity provides multiple questions that lead researchers step-by-step through the process of analyzing a primary source letter. An attachment includes a series of sample letters from World War II that class members can use to practice their analysis skills. The resource could be used as a practice set or as a lesson in itself.