Why are Hindi and Urdu usually treated as separate languages?

Hindi and Urdu are mutually intelligible and share the same Indo-Aryan base, grammar, and phonology, leading many to view them as a single language. However, they are treated as separate languages primarily due to historical, sociopolitical, and cultural factors rather than linguistic ones.12

The distinction is marked by several key differences:

• Lexical Sources: While they share a core vocabulary, they have borrowed extensively from different sources. Hindi draws heavily from Sanskrit, whereas Urdu incorporates significant vocabulary from Persian and Arabic.12
• Writing Systems: Hindi is written in the Devanagari script, while Urdu uses a modified Perso-Arabic script known as Nastaliq.1
• Sociopolitical Identity: During the 19th-century colonial era, efforts to standardize Hindustani became increasingly divisive. Religious and national identities led to the formal split of the language following the partition of India and Pakistan, with Hindi becoming an official language of India and Urdu the official language of Pakistan.2