The purpose of this study was to examine the usage aspect of learners’ expression strategies that appeared while writing and speaking Korean. To investigate this, the research team conducted the study based on reports written by foreign students and contents of compositions and presentations submitted for the final examination. Using these materials, we studied whether the subjects were aware of their expression strategies while writing and speaking Korean. In addition, we compared differences in the strategies chosen for writing and speaking. The results showed the following. First, learners recognized the expression strategy, which they revealed during the performance of the task. Through this, we confirmed that learners could avoid producing errors, although ‘strategic error’ tended to be generated in different ways depending on strategy used. Second, learners used different expression strategies for writing and speaking. However, there were some errors generated by ‘strategic absence’ in the areas of writing and speaking. As a result, we confirmed the great importance of ‘meta-cognition strategy’ in expression instruction. This study has significance as baseline data that examines the reality of Korean expression instruction and seeks improvement. However, it has a limitation in that the collected data and the learners’ individual characteristics are not revealed. A topic of further study would be to examine characteristics according to nationality, gender, and major of each learner, and to classify the impact of these criteria.