A systematic review of linguistic and metalinguistic studies in Persian-speaking individuals with intellectual disorder.

The purpose of this study is to analyze the Linguistic and Metalinguistic abilities of Persian-speaking individuals with Intellectual disorder to identify the areas and results of the research carried out in order to recognize their main linguistic features, the research gaps, and also guide future research. To this end, first, related keywords were searched and related topics were separated. Then, by reading the abstracts and, if necessary, the entire articles, the unrelated articles were removed. The articles were categorized and studied on linguistic and metalinguistic characters in four areas such as semantics, phonetics and phonology, morphology and syntax, and pragmatics. In addition, to investigate the effect of bilingualism and gender on the linguistic abilities of these individuals, the findings related to studies in the field of bilingualism and gender were examined in a separate section. From the general review of about 39 studies found, we found that in the fewest studies, the field of pragmatics was dealt with. The general results of the investigation were presented in the table of the results section in addition, in phonological studies, there was no significant difference in phonological awareness between girls and boys. In bilinguals, phonological awareness skills were related to their spelling skills.