🇬🇧 Best English books for intermediate learners

Foreign Service Institute, Peace Corps and DLI materials — full textbooks plus hundreds of hours of audio — are public domain and hosted here for free across dozens of languages. The depth is extraordinary and the FSI Basic courses take diplomats to professional working proficiency, which no consumer app attempts. The recordings are from the 1960s–80s, the drills are relentless, and some vocabulary is dated (Cold War era), so they suit disciplined self-studiers, not casual learners.

Each course is ~100 short bilingual dialogues with native audio: you passively absorb for months, then start an 'active wave' translating back into the target language. Books run around €30 (e-courses ~€50) across 70+ languages, and the method is a long-standing favourite among polyglots for reaching real reading fluency. Caveats: many courses are only published from French, the humour is dated, and it demands daily discipline with no gamification to carry you.

Over 70 languages, each a step-by-step beginner course written by an experienced teacher, and crucially all the audio is free to download from the companion site even if you find the book secondhand. Slightly more academic and grammar-forward than Teach Yourself, which some learners prefer. Like any book series the individual titles differ in quality; the less common languages are often the only decent course in existence.

Raymond Murphy's blue book has taught grammar to tens of millions of learners with a simple format — explanation and examples on the left page, exercises on the right — covering everything an intermediate learner needs, with an answer key that makes it genuinely self-study. The fifth edition adds an interactive ebook with audio. Companion volumes exist for elementary (red) and advanced (green) levels, so buy the one that matches you; and it is a practice book, not a course, with nothing on listening, speaking or vocabulary building.

Graded readers are the highest-return, least-used tool in English learning: these are novels, thrillers, classics and non-fiction rewritten within a controlled vocabulary for each of seven stages from A1 to C1, most with audio, so you can finish real books long before you could read the originals. Reading several at a comfortable level does more for fluency than grinding through one text that is too hard. They are paid, priced per title, and the simplifications strip out much of the original style — the point is volume of comprehensible reading, not literary appreciation.

The 'Complete' books are proper structured courses with dialogues, graded exercises and downloadable audio, and the range covers languages no app touches. Quality varies noticeably by title and author, so check reviews for your specific language before buying rather than trusting the series name. Their graded readers and 'Script Hacking' alphabet guides are also worth knowing about for non-Latin scripts.