This study investigated language learning strategies used by 418 EFL learners in Taiwan and looked for relationships between learning strategy use and the patterns of strategy use based on language proficiency. The participants reported using compensation strategies most frequently and affective strategies least frequently. The most frequently used individual strategies involved guessing intelligently and overcoming limitations in using English; the least used items involved speaking and writing to others in English. The research results also showed that proficiency level has a significant effect on strategy choice and use. The more proficient learners used more learning strategies. They used metacognitive strategies and cognitive strategies most frequently and memory strategies least frequently. The less proficient learners, on the other hand, preferred social and memory strategies to cognitive and metacognitive strategies. The research also analyzed individual strategy items, finding that the strategies reported as used more frequently by the more proficient learners were arranging and planning their learning; using analytical and reasoning skills; and practicing their pronunciation and speaking. (Contains 9 tables and 2 figures.)