Four main scripts stand out as being widely used in Jordan for official records and communications, and for monumental inscriptions.
The earliest evidence of Aramaic in Jordan goes back to the 9th century BC, following which the influence of Aramaic spread all over the Ancient Near East. Thus, although the Jordanian states of Ammon, Moab and Edom had their own “national” languages and scripts, there is obvious Aramaic influence in them. It is also assumed that Aramaic was an official language in Jordan during the Persian period (6th-4th centuries BC) since Aramaic was an official language of the Persian Empire. Then although Greek became the official language of the region as of the Hellenistic era, Aramaic remained in use in private and religious circles for several centuries.
The Nabataean Arabs used a late dialect of Aramaic, and a late off-shoot of the Aramaic script for their writings. The earliest inscription written in this Nabataean script goes back to the 2nd century BC, whereas the latest dates to AD 355. This demonstrates that the script’s usage was not limited to the period of Nabataean political hegemony, which ended in AD 106. The Nabataean script gradually shifted away from its Aramaic origin and took forms that were later adopted by the Arabic script.
Greek was an official language in Jordan from the end of the 4th century BC up to the 7th century AD. Two factors played a role in this: first was the incorporation of Jordan into the world of Hellenistic culture, following the conquests of Alexander the Great; the second reason was that Greek was the language of the Eastern Roman Empire as of the fourth century AD, which explains the dominance of Greek in the Levant instead of Latin under the Roman Empire. Greek remained in common official use until it was gradually replaced by Arabic during the Umayyad period.
Arabic was presumably widely spoken in Jordan before Islam, but only a few Arabic inscriptions were found from that era. Arabic replaced Greek as the official language in the region with the "Arabisation" of official records in around AD 700, during the reign of Abd al-Malik bin Marwan. After this move Arabic dominated in all aspects of life in the Arab World, including Jordan. Turkish, written in Arabic script, was also used as an official language in the region during the Ottoman period (1516-1917).
© From a wall text in the Jordan Museum