Spoken Hindi has 10 indigenous vowels (together with their 10 nasalized counterparts). The indigenous vowels are अ [ə], आ [a], इ [I], ई [i:], उ [ʊ], ऊ [u:], ए [e:], ऐ [ɛː], ओ[o] & औ [ɔː]. Apart from these, Hindi also has three vowels which are borrowed from other languages like Sanskrit or English. They are following –
- ऋ / ṛ / – a retroflex vowel borrowed from Sanskrit but pronounced commonly as /ri/
- /æː/ in English loanwords, such as /bæːʈ/ (‘bat’) – no separate orthographic sign in Hindi but expressed via ऐ (ai)
- ॉ / ऑ /ɒ / in English loanwords such as college, doctor, hostel etc.
Over the time, Hindi has borrowed a short-open-back-rounded vowel /ɒ / from English (as in English ‘hot’). This vowel is mostly pronounced by educated speakers of Hindi-Urdu familiar with English while speaking words like डॉक्टर (doctor), हॉस्टल (Hostel), कॉफ़ी (Coffee), कॉलेज (College) etc. Since Devanagari does not have a sign for this vowel, a new sign ॉ / ऑ was derived from the existing orthography. Looking at the vowel charts of English & Hindi, one can place ॉ / ऑ between long vowel /a/ and /ɔ/. Therefore ideally in Devanagari vowel chart of Hindi ऑ should be placed right before औ and hence in a Hindi dictionary, words like डॉक्टर should come before syllables such as डौ.
The revised Devanagari syllabary for Hindi vowels would look like this