Devanagari Letter Au

Its pronunciation depends on the language. In Sanskrit, au glides from an a-like sound toward u; Marathi generally has a similar glide. Standard Hindi usually has one long open o sound, written /ɔː/ in pronunciation guides.

औ starts a syllable without a consonant, as in Hindi और (aur, “and”). After a consonant, use the vowel sign ौ, called an au matra: क normally includes an a vowel; कौ (kau) replaces it with au.

Where did औ come from?

It evolved through earlier scripts, beginning with the Brahmi tradition. Brahmi is the ancient script used in Emperor Ashoka's inscriptions from the third century BCE. Early Brahmi had an au vowel sign, but apparently lacked the independent letter at that stage. Later au forms occur in scripts from the Kushana and Gupta dynasties. These precede Nagari, the script from which Devanagari developed.