The Collins Cobuild Advanced Learner's English Dictionary is an authoritative resource for English learners, distinguished by its use of full-sentence definitions drawn from a large corpus of real-world language, which helps users understand how words are used in context. Its corpus-based approach ensures authenticity and helps learners develop a deeper understanding of English by showing how words are used in natural patterns. It also includes features to build vocabulary skills, such as highlighting common structures and analyzing prefixes and suffixes.