For upper-intermediate and advanced learners of English. You can trust Collins COBUILD: all of our explanations, examples and special features are based on our 4.5-billion-word database of the English language, the Collins Corpus, which means you can trust COBUILD to help you speak and write accurate and up-to-date English. The corpus is updated every month and has been at the heart of Collins COBUILD for over 25 years. Be confident in English: up-to-date coverage of today’s English, with all words and phrases explained in full sentences; authentic examples from the Collins Corpus show how English is really used. Expand your vocabulary: thousands of synonyms, antonyms, collocations and illustrations of key topics; alternatives for the 50 most-overused words in the visual thesaurus; improve your fluency; the most frequent words are clearly labelled, showing which words to learn first; information on usage and common grammatical patterns illustrate how the English language works. CEFR B2+: ideal for students preparing for IELTS, TOEFL® and Cambridge English: First, Advanced and Proficiency.