Allophony of 'v' and 'w' in Hindustani
and are allophones in Hindustani. These are distinct phonemes in English, but both allophones of the phoneme ʋ (written <व> in Hindi or <و> in Urdu), especially in loanwords of Arabic and Persian origin. More specifically, they are conditional allophones, i.e. rules apply on whether <व> is pronounced as or depending on context. Native Hindi speakers pronounce <व> as in vrat ('व्रत' 'ورت', oath) and in pakwān ('पकवान', 'پکوان' food dish), treating them as a single phoneme and without being aware of the allophone distinctions, though these are apparent to native English speakers.
However, the allophone phenomenon becomes obvious when speakers switch languages. When speakers of other languages that have distinction between and speak Hindustani, they might pronounce <व و> in <व्रत ورت> as, i.e. as instead of the correct . This results in an intelligibility problem because can easily be confused for aurat, which means woman instead of oath in Hindustani. Similarly, Hindustani speakers might unconsciously apply their native allophony rules to English words, pronouncing war /wɔːɹ/ as or advance /ədˈvɑːns/ as adwance, which can result in intelligibility problems with native English speakers.
In some situations, the allophony is non-conditional, i.e. the speaker can choose, or an intermediate sound based on personal habit and preference, and still be perfectly intelligible. This includes words such as अद्वैत ادویت which can be pronounced equally correctly as or .