In the last decade, our field has seen enthusiastic interest in the role of vocabulary in foreign language courses. This recent interest has led to research with practical classroom applications for foreign language classrooms. In order to progress in a foreign language, learners need to be able to understand what they are hearing and reading. That is, the input must be comprehensible in order for it to be useful and meaningful to the learner and help with acquisition (Krashen, 1982), but if learners do not understand a sizable portion of the vocabulary in the language that they are reading or hearing, then this language is not comprehensible and therefore cannot be useful for acquisition. Many argue that vocabulary is one of the most important—if not the most important—components in learning a foreign language, and foreign language curricula must reflect this.