Sindhi is 46th most spoken languages of the world. 0.39% population of the world speaks it as a 1st language.
Before the advent of Islam in Sindh (711 A.D.), the language was prevalent in the region. But, over the course of centuries, Sindhi culture absorbed Arabic and Persian words which further enriched its heritage.
Sindhi became a popular literary language between the 14th and 18th centuries. This is when mystics or Sufis such as Shah Abdul Latif, Sachal Sarmast, Lal Shahbaz Qalandar (as well as numerous others) narrated their theosophical poetry depicting the relationship between humans and Allah.
As for writing scripts of Sindhi, before the standardization of Sindhi orthography, numerous forms of the Devanagari and Lunda (Laṇḍā) scripts were used for trading, universally by all Sindhis.
For literary and religious purposes, a modified form of the Persian alphabet known as Ab-ul-Hassan Sindhi and Gurmukhi (a subset of Laṇḍā) were used.
Another two scripts, the Khudabadi alphabet, and Shikarpuri were attempted to reform the Landa script.
In the year 1868, the Bombay Presidency assigned Narayan Jagannath Vaidya to replace the Abjad used in Sindhi, with the Khudabadi script. The script was decreed a standard script by the Bombay Presidency thus inciting anarchy in the Muslim-majority region. A powerful unrest followed, after which Twelve Martial Laws were imposed by the British authorities.
During British rule in the late 19th century, after much controversy, the Arabic-based orthography was decreed as a standard and a variant of the Persian alphabet was adopted for Sindhi. It is used in Pakistan today. It has a total of 52 letters, augmenting the Persian with digraphs and eighteen new letters (ڄ ٺ ٽ ٿ ڀ ٻ ڙ ڍ ڊ ڏ ڌ ڇ ڃ ڦ ڻ ڱ ڳ ڪ) for sounds particular to Sindhi and other Indo-Aryan languages. Some letters that are distinguished in Arabic or Persian are homophones in Sindhi.
Following Sindhi, dialects are spoken in Sindh.
1. Saraiki is spoken in Upper Sindh.
2. Vicholi is spoken in Central Sindh.
3. Lari is spoken in Laru (Lower Sindh).
4. Lasi is spoken in Lasbelo, a part of Kohistan in Baluchistan and the western part of Sindh.
5. Thari or Thareli, also known as Dhatki in Tharu is spoken in the desert region on the southeast border of Sindh and a part of the Jaisalmer district in Rajasthan.
6. Kachhi or Kutchi is spoken in the Kutch region and in a part of Kathiawar in Gujarat, in southern Sindh.