This research intends to identify some of the common lexico-grammatical errors Korean secondary school students make in learning English. The data used in this research consists of an about 33,000-word corpus of English written by grade 9 and 10 students. The corpus was scanned to retrieve all examples of misuse of such error-prone word forms as BECAUSE, HAVE, MANY, MUCH, IF, and A LOT OF, using the standard text retrieval software tool, WordSmith Tools. These word forms were compared with those in English textbooks used in middle school English classes in order to investigate how close students' use of these forms is to the taught forms. Overall, it is necessary to provide the students with corpus-based learning methods to acquire some problematic word forms, such as BECAUSE, MANY and A LOT OF. Techniques of drawing students' attention to form or noticing features of targeted items can be useful as well. Although this research could not find all the most common errors the students produce in learning English, it could be one way of identifying significant features of learner errors, in particular areas of common difficulty in writing. It could also play an important role in developing more systematic learner language research and designing learner corpus-based teaching techniques and materials.

Abstract
Ⅰ. Introduction
Ⅱ. Development of Learner Language Research
Ⅲ. Computer-aided Learner Language Research
Ⅳ. Data and Analysis
Ⅴ. Results and Discussion
Ⅵ. Implications for Future Work
References
Appendix

• Dong Ju Lee(University of Essex)