EN
This case study investigates the effectiveness of the application of the blended approach to teaching a foreign language. The approach can be defined as a combination of a face-to-face classroom component with online instruction (Graham 2003). In the present study the element that was blended within the face-to-face component was asynchronous computer mediated communication in the form of e-mail exchanges between a native speaker of English and a Polish learner of English. The effectiveness of the approach was measured in terms of expanding vocabulary knowledge. The findings revealed that e-mail correspondence treated as an integral part of a language course helped the student to expand her vocabulary, eliminate the majority of spelling mistakes and influenced the complexity of her writing.