linguistic:paraphrasing, structural:reformatting
Regional languages

Although Middle Persian was the native language of the Sasanians (who, however, were not originally from Pars), it was only a minority spoken-language in the vast Sasanian Empire; it only formed the majority of Pars, while it was widespread around Media and its surrounding regions. However, there were several different Persian dialects during that time. Besides Persian, the unattested predecessor of Adhari along with one of its dialects, Tati, was spoken in Adurbadagan (Azerbaijan). Unwritten Pre-Daylamite and probably Proto-Caspian, which later became Gilaki in Gilan and Mazandarani (also known as Tabari) in Tabaristan, were spoken about in the same regions. Furthermore, some other languages and dialects were spoken in the two regions.

In the Sasanian territories in the Caucasus, numerous languages were spoken including Old Georgian, various Kartvelian languages (notably in Lazica), Middle Persian, Old Armenian, Caucasian Albanian, Scythian, Koine Greek, and others.

In Khuzestan, several languages were spoken; Persian in the north and east, while Eastern Middle Aramaic was spoken in the rest of the place. Furthermore, late Neo-Elamite may also have been spoken in the province but there are no references explicitly naming the language. In Meshan, Strabo divided the Semitic population of the province into "Chaldeans" (Aramaic-speakers) and "Mesenian Arabs". Nomadic Arabs along with Nabataean and Palmyrene merchants are believed to have added to the population as well. Iranians had also begun to settle in the province, along with the Zutt, who had been deported from India. Other Indian groups such as the Malays may also have been deported to Meshan, either as captives or recruited sailors. In Asoristan, the majority of the people were Aramaic-speaking Nestorian Christians, notably including Middle Syriac, while the Persians, Jews and Arabs formed a minority in the province.

Due to invasions from the Scythians and their sub-group, the Alans, into Atropatene, Armenia, and other places in the Caucasus, the places gained a larger, although small, Iranian population. Parthian was spoken in Khorasan along with other Iranian dialects and languages, while the Sogdian, Bactrian and Khwarazmian languages were spoken further east in places which were not always controlled by the Sasanians. To the further south in Sakastan, which saw an influx of Scythians during the Parthian period, much later the place of Sistanian Persian, an unknown Middle Southwestern Iranian language was spoken if it was not likely Middle Persian as well. Kirman was populated by an Iranian group which closely resembled the Persians while, farther to the east in Paratan, Turan and Makran, non-Iranian languages and an unknown Middle Northwestern Iranian language were spoken. In major cities such as Gundeshapur and Ctesiphon, Latin, Greek and Syriac were spoken by Roman/Byzantine prisoners of war. Furthermore, Slavic and Germanic were also spoken in the Sasanian Empire, once again due to the capture of Roman soldiers but this must have been negligible. Semitic languages including Himyaritic and Sabaean were spoken in Yemen.