The Investigation of the Lexis of Thought: A Corpus-Based Study of Cognitive Nouns “Idea,” “Thought,” and “Notion” in American English

Abstract

This corpus-based study investigates the near-synonymous cognitive nouns idea, thought, and notion using the Corpus of Contemporary American English (COCA). The analysis examines genre distribution and verb–adjective collocational patterns to identify usage-based constraints on their interchangeability. Frequency results show that thought is the most frequent overall, idea occurs most often in informal genres such as blogs and TV/movie subtitles, and notion is strongly associated with academic texts. To examine semantic behaviour, the top 20 verb and adjective collocates of each noun were extracted using combined frequency measures and a Mutual Information threshold (MI ≥ 3). These collocates were grouped into semantic categories based on shared meanings, with reliability ensured through expert validation, yielding an inter-coder agreement rate of at least 85%. The findings reveal both overlap and distinction: all three nouns share evaluative themes such as NEGATIVE SENSE, UNCERTAINTY, and CONCEPTUAL meaning, while idea aligns with proposal-oriented contexts, thought with temporal and clarity-related meanings, and notion with accepted and distributive meanings in academic discourse. Pedagogically, the results highlight the value of teaching these nouns through genre awareness and collocational patterns. Explicit comparison of expressions such as reject an idea, share a thought, and support a notion can enhance EFL and ESL learners’ lexical accuracy and contextual appropriateness.