This document provides an introduction and background on language learning strategies. It discusses how the focus of second language acquisition research has shifted from the teacher to the learner and the learning process. It also summarizes some key literature on language learning strategies, including common classifications of strategies into cognitive, metacognitive and social categories. The document introduces the research topic of comparing language learning strategies used by different groups of learners, including college students, English teachers and office workers. It outlines the problem statement, significance, objectives and limitations of the study.