This paper specifies the assessment of those language skills that are needed for effective writing by students in grades one through six. Specifications are included for language skills such as language usage, grammatical knowledge, diction, sentence production, specific writing techniques, and verse (poetry) skills. An introductory section provides background materials, including explanations of how the skill specifications were selected and how they are presented in this report. In the sections that follow the introduction, the language skills are discussed, a table listing the language skills is presented, and the specifications are described for each skill. Each skill is described in detail, followed by the presentation of sample assessment items and descriptions of how these items are constructed. (Four related documents provide assessment specifications for other writing skills, including mechanics, spelling, general discourse, and specific discourse products.) (RL)