This case study investigates the effectiveness of t he application of the blended approach to teaching a foreign language. The approach can be de fine 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 betwe n 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 reveal ed that e-mail correspondence treated as an integral part of a language course helped the st uden to expand her vocabulary, eliminate the majority of spelling mistakes and influenced the co mplexity of her writing. INTRODUCTION In recent years the growing support for the integra tion of computers in language education can be observed. The degree of integration differs rom visiting a computer laboratory once in a while to distance learning which completely elimi nates the classroom component. The proponents of distance education claim that this ty pe of course design offers greater autonomy and flexibility. These advantages cannot b e denied, however, as several studies indicate, not all students are ready to completely substitute the teacher, the classroom and the textbook with the computer (Krajka, 2002; Kilickaya , 2007). Hence, a combination of a faceto-face classroom element with the online instructi on, popularly referred to as blended learning, has become the alternative that is gainin g popularity among language educators. So far several studies reported that the provision of blended learning courses is highly appreciated and positively rated by the students (D elialioglu and Yildirim, 2007; MossavarRahmani and Larson-Daugherty, 2007; Akkonyunlu and Soylu, 2008). The types of e-learning activities that are to be int grated into the course largely depend on the tutor and the needs of the students, a d can vary from WebQuests, using blogs or learning platforms to chatting. The central comp nent of the present study was asynchronous computer mediated communication in the form of an e-mail exchange. The Teaching English with Technology, vol. 10, no. 1, pp. 3-30, 4 reason behind the choice was strictly connected wit h the fact that the integration of e-mail exchanges offers a real purpose for communication w hich is the benefit that cannot be substituted with a textbook alone. PREVIOUS RESEARCH Many researchers who used e-mail exchanges reported n numerous positive outcomes of such collaborations. Warschauer (1995) points to en couraging equal participation in the classroom as according to his study, those students who were hesitant to express themselves in the classroom context were more willing to parti cipate in the online environment. Kelm (1996) adds personalizing the process of learning a s another advantage. Gonglewski et al. (2001) enumerate promoting student-centred learning as well as expanding topics beyond classroom-based ones as further benefits. Warschaue r and Healey (1998) as well as Dudeney (2000) mention opportunities for authentic use of l anguage as an advantage since students have a real audience to communicate with. O’Dowd (2 003) points to culture-related benefits including creating cultural connections to the TL a nd raising cultural awareness. Although these studies revealed a great deal of be nefits, they omitted the linguistic advantages that such exchanges bring. The study tha t reported on improvement of lexical density and complexity of the participant was St Jo hn and Cash’s research (1995). Here, however, even though the learner took part in a reg ular course, its content was not connected in any way with what has been discussed during the exchange. It is believed that creating a link between the course and the exchange and a more deliberate focus on forms used in emails, applied in the present study, would turn out to be even more profitable to the participant. BLENDED LEARNING AND VOCABULARY LEARNING The assumption that blended learning would contribu te to the enhancement of vocabulary knowledge is rooted in principles underlying vocabu l ry learning. First of all, the student has a chance to work on all aspects of knowing a word i .e. the spelling, the meaning, the phonological representation and the grammatical kno wledge (Schmitt, 2000). The opportunities for that are created both during the lesson and through the correspondence. The acquisition of the written form is promoted through encounters with the written form in the letters and the ability to produce them when replyi ng. The exchange creates opportunities to elicit the meaning from the context and the lesson part determines if guessing from the context is correct, as well as eliminates any misco nceptions. The ability to understand sounds Teaching English with Technology, vol. 10, no. 1, pp. 3-30, 5 and produce them is checked during the speaking par t of the lesson. Deliberate practice of grammatical structures is provided through explicit ins ruction during the lesson. The blended approach also encompasses all the proc sses necessary for establishing vocabulary knowledge, namely noticing, repetition/r etrieval and generative use (Nation, 2001). Both components support noticing as the stud ent is presented with an opportunity to notice the gap in his or her knowledge by compariso n with the native speaker and choose these words which he/she finds useful in further le arning experiences. Additionally, some vocabulary items are pointed out to the student dur ing the lesson. Opportunities for retrieval are created immediately as a student can practice t he newly acquired items both in writing when replying to his/her partner and also during th e speaking part of the lesson. Generative use of newly learnt items is also reinforced by bot h components as it can take place when discussing a problem orally and/or in writing. A good language training programme should ensure b oth incidental and intentional learning, as the combination of both guarantees tha t the items will be remembered (Schmitt, 2000; Nation, 2001). Blended learning meets that re qui ment as the incidental part occurs when the learner is corresponding with the native s p aker. Intentional learning takes place during face-to-face instruction when the teacher pr ovides deliberate discussion of structures and vocabulary items which could be problematic for the non native speaker and could be an impediment for unrestrained communication. OBJECTIVES AND THE SIGNIFICANCE OF THE STUDY The majority of previous research that used CMC in teaching a foreign language was not conducted within the blended approach context. Addi tionally, it focused on other beneficial aspects, pushing aside improving linguistic skills. Hence, this research will attempt to address the following questions: 1. Will the NNS notice and use new vocabulary items us ed by the NS in his e-mails? 2. Will those items be remembered once the exchange is finished? 3. What other advantages can blended learning, with email exchanges included as an online component, bring to a foreign language learn r? Other benefits that are addressed here refer both to other linguistic skills as well as increased motivation and improved intercultural kno wledge. The evidence to support that will come from two sources. The correspondence will prov ide the insight into the improvement in other linguistic skills. On the basis of the partic ipant’s impressions expressed during the post Teaching English with Technology, vol. 10, no. 1, pp. 3-30, 6 research interview some conclusions regarding other beneficial aspects of the approach will be drawn. DESIGN OF THE STUDY The project took the form of a single case study. T he subject was a 25 year-old intermediate student from Poland (NNS) corresponding with a 26-y ear-old native speaker (NS) of English. In accordance with the blended learning definition the course consisted of two components: the online part in the form of e-mail exchanges bet we n the two participants and a regular lesson. Prior to the commencement of the study, the partic ipants were requested to provide a list of topics that would be of interest to them. I n order to make the research meaningful for both sides the participants chose the topics which were a combination of controversial discussion provoking subject matters and those whic h demanded a comparison between the two cultures, introduced cultural differences and r aised cultural awareness. The material for the discussion was provided by th e researcher in the form of a newspaper article, a movie trailer or a short film depending on the topic. The materials were chosen according to both participants’ interests an d matched or slightly exceeded the NNS’ level of the foreign language command. Additionally , they had to be controversial enough so that they kept the participants engaged in the conv ersation. The materials derived from such sources as the Guardian, the Washington Post , BBC news, Yahoo news and Other articles were copied from three textbooks tha t were used for the purpose of this study, namely Taboos and Issues , Ideas and Issues and Britain Explored. Both participants received an e-mail from the researcher which contained links to appropriate materials if they could be found online. If the materials were copied from tex tbooks they were handed in to the NNS before the lesson and it was her task to refer to t hem in the correspondence.