For a variety of reasons, learning English prepositions is notoriously difficult and a slow, gradual process for English as a Second Language (ESL) students. To begin, English prepositions typically are short, single-syllable or two-syllable words that are seldom stressed when speaking and therefore often not articulated clearly or heard distinctly. Another problem is that prepositions are often conceptually different from one language to the next, and direct translation cannot be relied on. The nature of prepositions obliges ESL students to rely on wide reading, memorization, and dictionaries to learn them. One way to help students is to introduce "consciousness-raising," a technique that focuses attention on correct grammatical forms by highlighting or emphasizing them in some way. According to Ellis (1997), noticing a grammatical feature is a necessary and fundamental pre-condition for learning it. Unlike formal grammar instruction, consciousness-raising does not require the learner "to verbalize the rules he has learnt" (Ellis 1985, 244), but instead alerts learners to a particular grammatical feature. In this article, the author discusses the need for consciousness-raising activities for prepositions and describes how she used the technique to promote correct usage of English prepositions in an Advanced Certificate in Education (ACE) course for secondary school ESL teachers in South Africa. (Contains 2 figures.)