This chapter first explores early grammarians’ accounts of the interjection and then elaborates on thirteenth-century grammarians’ analysis of interjections, communication rather than formal grammar, and the role of affectus, feeling, and emotion within grammar and semantics. The grammarians stretched the idea of verbal meaning to include both cognitive and affective signification as understood in specific contexts. Priscian (Institutiones, 2.15) provided grammarians with a framework for contrasting assertive sentences referring to substances with nonassertive sentences or interjections signifying mental dispositions or affects. These grammarians situated grammar and usage within interpersonal speech contexts.