This study examines how both native English speakers and advanced Persian speakers of English process relative clauses, which are parts of sentences providing more information about a noun. The research focuses on how these groups interpret sentences where the relative clause could attach to one of two possible nouns. By manipulating whether these nouns are definite or indefinite (i.e., 'the nurse' versus 'a nurse'), the study investigates if definiteness—a discourse cue—affects their attachment preferences. The findings reveal that both groups show a preference for attaching the relative clause to the noun closest to it when the noun is definite. This challenges theories suggesting that native and non-native speakers use different cognitive strategies for sentence processing, particularly in contexts where discourse-based cues like definiteness are involved.