This patent specification details a system for enhancing search queries by using concepts, which are groups of words with a unified meaning, as contextual clues for suggesting better search terms. The system identifies these concepts within a user's query and then analyses historical search data to find common substitutions for other terms appearing alongside these concepts. By understanding the context provided by a concept like "New York Times", the search engine can more accurately suggest replacing "Puzzle" with "Crossword" compared to a general substitution. This approach allows for more nuanced and relevant query revisions by considering multi-word contexts without excessive computational load, ultimately aiming to improve search result quality.