This document summarizes a study that compares how children and adults acquire articles in English as a second language. The study found that both children and adults are influenced by the semantic feature of specificity when using articles. However, adults overextend this and incorrectly use articles in both definite and indefinite contexts, while children only make mistakes in indefinite contexts. The study concludes that both children and adults rely on implicit linguistic knowledge of semantic universals, but adults also develop explicit strategies that lead to overgeneralization of article rules.