In the paper the authors introduce the methodology and selected findings of a research project that focused on teachers’ and pupils’ utterances during English instruction as it was realized on lower-secondary level in the Czech Republic. The authors introduce systems of categories that were developed to be used to discover the proportions between the target language and the mother tongue and to capture and describe the nature of pupils’ utterances during instruction. The research builds on the concept of the communicative approach in the teaching and learning of English. The main research method was video-mediated observation – video study and transcript analysis. We analysed 79 transcripts; the analytical unit was a 10-second interval. The findings indicate that there are vast differences in classroom organisation and in opportunities to talk that are offered to pupils.