This paper presents an analysis of teachers' questions and students' responses in content and language integrated learning (CLIL) classes of history. Through the combined application of genre theory and a typology of CLIL teacher academic questions, the study aims at contributing to the understanding of how CLIL students use the foreign language to express academic meanings. The data are part of the UAM-CLIL project, which focuses on the systemic-functional analysis of CLIL students' language production. In this paper, we analyze class discussions on various topics in two secondary schools. These discussions were carried out at the end of a topic and followed a prompt that aimed at triggering participation in different history genres: recount, account, explanation and argument. The aim of the study is twofold: first, the academic questions used by the teachers are classified in relation to the genre triggered by the prompt; second, we analyze the length and complexity of the students' responses. The results show that the teachers did not always ask the questions related to the prompt. In fact, they frequently used questions for facts, which usually triggered shorter and less complex responses than other types.