 Along with Peter of Spain, Lambert of Auxerre, and Roger Bacon, William of Sherwood was one of the first terminist logicians, working in a context where the newly discovered and translated Aristotelian material of the 12th century had become fully integrated into the logical and philosophical curricula through the works of people such as John le Page (Uckelman &amp; Lagerlund, 2016). The terminist period of logic was marked by the development of logical genres and techniques that go beyond Aristotle and mere commentaries on his works. The two primary branches of terminist logic are the study of the properties of terms and the study of the meaning and function of syncategorematic words. Sherwood’s Introduction picks up the first of these two branches in its fifth chapter, and his Syncategoremata deals with the second. The remainder of the Introductiones is devoted to the standard Aristotelian material: Chapter One on statements corresponds to On Interpretation; Chapter Two on predicables to the Categories; Chapter Three on syllogisms to the Prior Analytics; Chapter Four on dialectical reasoning to the Topics; and Chapter Six on sophistical reasoning to the Sophistical Refutations. We will focus our attention in this article on the unusual or distinctive aspects of his logical and semantic theory, as found in Chapter Five of the Introduction and in the Syncategoremata.