The Arabic language is spoken in sixteen modern states alongside the historical Silk Road. Classical Arabic is used for religious and ceremonial purposes, having an archaic vocabulary. Modern Standard Arabic is a modernized variety of Classical Arabic. In most Arab countries only the well-educated have adequate proficiency in Standard Arabic, while over 100,500,000 do not.

Pashto is a member of the southeastern Iranian branch of Indo-Iranian languages spoken in Afghanistan, Pakistan and Iran. There are three main varieties of Pashto: Northern Pashto, spoken mainly in Pakistan; Southern Pashto, spoken mainly in Afghanistan; and Central Pashto, spoken mainly in Pakistan.

Persian is an Iranian language within the Indo-Iranian branch of the Indo-European languages. It is primarily spoken in Iran, Afghanistan , Tajikistan, and countries which historically came under Persian influence. The Persian language is classified as a continuation of Middle Persian, the official religious and literary language of Sassanid Iran, itself a continuation of Old Persian, the language of the Persian Empire in the Achaemenid era.

Swahili is the national language of Tanzania, spoken by at least 15,000,000 people across the country (according to a survey from 2012). It is also the national language of Kenya, where the language is known as Kiswahili, and is spoken in Somalia. Read more about this language on the Ethnologue website.

Urdu is an Indo-Aryan language and the national language of Pakistan, and is closely related to and mutually intelligible with Hindi, though a lot of Urdu vocabulary comes from Persian and Arabic, while Hindi contains more vocabulary from Sanskrit. Linguists consider Standard Urdu and Standard Hindi to be different formal registers both derived from the Khari Boli dialect, which is also known as Hindustani. At an informal spoken level there are few significant differences between Urdu and Hindi and they could be considered varieties a single language.

The Chinese language (汉语/漢語 Hànyǔ; 华语/華語 Huáyǔ; 中文 Zhōngwén) is a language or language family consisting of varieties which are mutually intelligible to varying degrees. Originally the indigenous languages spoken by the Han Chinese in China, it forms one of the branches of Sino-Tibetan family of languages.

Azerbaijani or Azeri (Azərbaycanca, Azərbaycan dili) is a language belonging to the Turkic language family, spoken in southwestern Asia by the Azerbaijani people, primarily in Azerbaijan and northwestern Iran. Azerbaijani is member of the Oghuz branch of the Turkic languages and is closely related to Turkish, Qashqai, Turkmen and Crimean Tatar.

The national language of Mongolia, Mongolian is spoken by 2,330,000 people across the country (according to a census from 1995). It is also spoken in the Buryat region of the Russian Federation. Read more about this language on the Ethnologue website.