We investigated the circumstances in which 3- to 5-year-old children can and cannot interpret adjectives flexibly. In Experiment 1, children were required to interpret big and little both in reference to a basic level kind (e.g., “This is a big marble”) and in reference to a superordinate kind (e.g., “This is a little toy”). Experiment 2 examined 3-year-olds’ flexible interpretation of big and little with respect to a medium-sized stimulus that was alternately compared with a smaller stimulus and a larger stimulus (e.g., “Which one of these two circles is the big one?”). Even the youngest children switched between interpretations when the switch was accompanied by a change in the stimulus display. When the stimulus display remained constant, however, younger children typically perseverated on a single interpretation. Results replicate evidence of the roots of flexible adjective interpretation but also show protracted development of the ability to coordinate two incompatible interpretations of a single situation.