An investigation on the identity work of a prospective teacher is conducted to better understand how the participant argued for recognition of her projective mathematics teacher identity. Characteristics of the claims, evidence, and anticipatory statements used are explored. Using an argumentation framework, the participant's discourse demonstrated differing strengths for the claims she was making. These were referred to as levels of ownership depending on the number of criteria met (I-statements, hedging, and intensifiers). This helped find the ideas central to how she wanted to be perceived as a mathematics teacher. Evidence for the participant's claims came in two different ways, anecdotal and belief oriented. The anticipatory statements were used in three ways, (a) to provide details; (b) to recognise constraints or limitations; or (c) to enact defensive/protective practices.