Just add "er"

Alice recently had a grammatical realization: one who runs is a runner; one who bakes is a baker.

Wearing a tutu, she demonstrates her new understanding of language.

Alice: I a balleter ( ed - pronounced: bah-layer ). You the watcher. Sit on the couch.

Later, in addition to the tutu, she sports a cowboy hat.

Alice: I a ballet giddy-upper.