Fatih Bayram

Individual variation in heritage language (HL) outcomes does not seem to be random. Instead, this variation can be related to the specific exposure and use patterns heritage speakers (HSs) have with their languages in the contexts they reside. In this study, we present data from 38 child HSs of Persian in English dominant contexts (in New Zealand and the UK), their mothers as well as a control group of age-matched monolinguals in Iran. All participants completed a film-retelling task from which their lexical sophistication (LS) and clausal density (CD) were measured. In addition, the HSs’ mothers completed a sociolinguistic questionnaire for their children which was used to calculate proxies for language experiences. Out of the two linguistic measures, the HSs differed from monolinguals only in LS scores. Regarding the relationship between HSs’ linguistic scores and language experiences, Random Forest analyses showed HL literacy to be the most important variable for the CD scores; while it was the HSs’ age-at-testing for LS. The mothers’ scores were only important for the HSs’ LS scores. This study contributes to the ongoing discussions on the nature of HL development, outcomes and individual variation.