Collins Cobuild Key Words for IELTS Book 2: Improver is a resource. It works best as a supplementary vocabulary builder, not a core textbook. Its corpus-based word selection is solid, but the activities lack cognitive depth and exam-task alignment. For a “deep” study, learners should combine it with authentic IELTS materials and an error-tracking system.

: The book includes an alphabetical A-Z section for easy look-up (dictionary style) and a thematic word list section categorized by common IELTS topics like health, education, and cities.