Abstract
BACKGROUND: In contrast to most other languages, where the spoken and written words are similar, children that have mastered Spoken Arabic (SA) learn to read a new written form of Arabic usually called Literary Arabic (LA). This phenomenon is called "diglossia". METHODS: Based on a series of studies comparing monolingual Arabic speaking and bilingual children, it has been suggested that Arabic speaking individuals develop metacognitive abilities that are considered bilinguals de facto. Some of the cognitive functions that would seem to benefit from fluency in more than one language are metalinguistic and metacognitive awareness. RESULTS: This review article summarizes the results of studies on the relationship between bilingualism, diglossia and executive functions (EFs) which involve metacognitive awareness, selective attention, control of inhibition and cognitive flexibility as well as working memory (phonemic manipulation and metalingual performances). CONCLUSIONS: The findings are in line with research results that have shown that bilingualism has a positive effect on the functioning of an individual's attentional system across the lifespan. The neural basis of diglossia in Arabic, as well as the conclusions and implications drawn from the impact of diglossia on EF and on reading in Arabic, are discussed.