Comparing Iranian High School Books and Interchange through Nominal

Abstract

The present study adopts a descriptive–analytical, library-based approach to compare Iranian high school English textbooks with the Interchange series in terms of nominal elements, lexical combinations, the Lexical Approach, prefabricated chunks, and lexical collocations. The main aim is to examine how noun phrases and collocation patterns are represented and distributed in these two widely used educational series, and to assess the extent to which each supports learners in acquiring the lexical and grammatical knowledge needed for fluent and accurate language use. The findings indicate that the Interchange series, owing to its communicative organization and use of authentic-style discourse, exposes learners to a wider range of complex noun phrases, formulaic lexical combinations, prefabricated chunks, and high-frequency collocations, and integrates syntactic and semantic knowledge more effectively. In contrast, Iranian high school textbooks tend to focus on isolated vocabulary and sentence-level grammar, presenting mainly simple noun phrases with limited post-modification. This gap may lead Iranian learners to produce grammatically acceptable but collocational deviant combinations. The study concludes with pedagogical implications for curriculum revision, materials adaptation, teacher training, and further empirical research on the impact of textbooks on learners' writing and speaking performance