This dictionary investigates how the patterns of contemporary spoken and written English can be presented in a format that facilitates easier access for intermediate to advanced learners. The work, overseen by John C. Sinclair, utilizes a massive corpus of real-world language usage drawn from books, magazines, and newspapers to provide a descriptive rather than prescriptive account of the language. By prioritizing frequency and natural phrasing, the text establishes a framework where definitions are constructed using clear, controlled vocabulary to ensure maximum comprehension for non-native speakers.

The Collins COBUILD series is widely regarded as a significant shift in lexicography for its reliance on corpus linguistics to reflect actual language usage. Its focus on natural phrasing and grammatical context makes it a standard reference tool for learners seeking to understand English as it is authentically spoken and written.