The notion of 'the first person' is centrally invoked in philosophical discussions of selfhood, subjectivity, and personhood. We ask whether this notion, as invoked in these discussions, is con-tingently or essentially a grammatical term. While it is logically possible that the linguistic dimensions of self-reference are accidental to this phenomenon, we argue that no explications of such phenomena as 'reference de se' or 'essential indexicality' in non-grammatical terms has been or likely can be provided, since grammatical factors uniquely co-vary with the forms of self-reference in question. The role of grammar is reinforced by the fact that species-specific forms of reference are never purely lexical and always have a structural signature involving specific grammatical configurations; and by findings that in cognitive disorders independently characterized as disorders of selfhood, such as autism spectrum conditions, the pronominal system proves to be a particular locus of vulnerability. We conclude that grammar and human-specific forms of selfhood form an inextricable unity, inviting renewed attention to language as a constitutive condition of personhood in at least some of its forms.