Learners of a new language need to acquire a huge amount of vocabulary. To get a sense of the size of the task, consider the following: Investigations of reading comprehension consistently show that learners of English have good understanding of a text written for native speakers only when an average of one word (or less) in every 50 is unfamiliar. It is estimated that knowledge of as many as 8,000 (!) word families is needed to reach that criterion. (The term “family” refers to a base word and its inflected and derived forms. For example, the sharp family includes sharper, sharpen, sharply, unsharpened, sharpness, and so on.) Since the task is clearly very large, it is important that vocabulary teaching be as efficient and effective as possible. The recommendations that follow are made with that reality in mind.