This thesis was written with non-native learners of Chinese in mind. Learning a foreign language, such as Chinese, is challenging. One of the most challenging aspects of learning a language is acquiring vocabulary. We simply do not just memorize words in dictionaries. Acquiring vocabulary involves meaningful and repeated interactions with the target words. It requires what Decarrico (2001) calls deep level processing. Instructors have a difficult task: when teaching vocabulary, they must encourage deep level processing, which helps students retain what they learn. Key-Consonant Theory evolved out of one language instructor's desire to help his students with the challenging task of learning vocabulary. Bar-Lev's theory states that Key-consonants are Semantic Keys, or "Determinatives," giving a helpful hint about the whole word's meaning.