This article reports on two novel word-learning experiments examining children's use of subject animacy to categorize novel adjectives as either "tough" adjectives (e.g., "easy," "hard") or control adjectives ("afraid," "eager"). In Experiment 1, a group of 4- to 7-year-olds watched videos with story contexts whose dialogues contained novel adjectives. Across two conditions of the experiment novel adjectives were used with either animate or inanimate subjects. Children categorized those adjectives used with inanimate subjects as "tough" adjectives. Experiment 2 presented 3- and 4-year-olds with video dialogues lacking story contexts but containing, depending on the condition, animate or inanimate subjects. Results show that children as young as 3 can categorize novel adjectives as "tough" adjectives when they are encountered with an inanimate subject, but older children (age 4 and up) also require semantic situational cues in categorizing these predicates.