Due to the internationalisation of higher education, the use of English at higher education institutions has become widespread. Today an increasing number of students participate in courses with the local language as medium of instruction but with textbooks in English. These have been called parallel-language courses, because they are expected to facilitate learning disciplinary discourse in two languages: the local language and English.

This thesis reports an exploration of Swedish students' reading and learning from English textbooks in parallel-language courses. The overarching aim was to investigate the relationship between the students' Swedish and English reading habits and reading proficiency, their academic biliteracy, and incidental learning of subject-specific terminology in English from reading. The study also set out to identify pedagogical solutions to facilitate students' reading and learning from reading in English.

The investigation comprised four studies which utilised a variety of methods and approaches, both qualitative and quantitative. Participants were Swedish and British students of biology and Swedish students of English.

The results show that many Swedish students are capable of reading and learning from texts in Swedish and English without experiencing serious difficulties, although additional support is required for the learning of English terminology. The findings also indicate that some students' difficulty when reading in English is not due to poor English language proficiency, but rather a range of other factors such as weak general literacy skills, low motivation, low subject and vocabulary knowledge, note-taking strategies, slow reading speed, and time. For some students, learning is also rendered difficult by their self-perceptions and beliefs about reading and learning.

Based on my findings, I propose a range of practices for EAP and subject teachers to adopt in order to improve reading and learning in parallel-language courses.