Schwa deletion in Indo-Aryan languages


Schwa deletion, or schwa syncope, is a phenomenon that sometimes occurs in Hindi, Urdu, Bengali, Kashmiri, Punjabi, Gujarati, and several other Indo-Aryan languages with schwas that are implicit in their written scripts. Languages like Marathi and Maithili with increased influence from other languages through coming into contact with them — also shows a similar phenomenon. Some schwas are obligatorily deleted in pronunciation even if the script suggests otherwise.
Schwa deletion is important for intelligibility and unaccented speech. It also presents a challenge to non-native speakers and speech synthesis software because the scripts, including Devanagari, do not tell when schwas should be deleted.
For example, the Sanskrit word "Rāma" is pronounced "Rām" in Hindi. The schwa sound at the end of the word is deleted in Hindi. However, in both cases, the word is written राम.
The schwa is not deleted in ancient languages such as Sanskrit or Pali.

Hindi

Although the Devanagari script is used as a standard to write Modern Hindi, the schwa implicit in each consonant of the script is "obligatorily deleted" at the end of words and in certain other contexts, unlike in Sanskrit. That phenomenon has been termed the "schwa syncope rule" or the "schwa deletion rule" of Hindi. One formalisation of this rule has been summarised as ə → ∅ /VC_CV. In other words, when a schwa-succeeded consonant is followed by a vowel-succeeded consonant, the schwa inherent in the first consonant is deleted. However, this rule sometimes deletes a schwa that should remain and sometimes fails to delete a schwa when it should be deleted. The rule is reported to result in correct predictions on schwa deletion 89% of the time.
Schwa deletion is computationally important because it is essential to building text-to-speech software for Hindi.
As a result of schwa syncope, the Hindi pronunciation of many words differs from that expected from a literal Sanskrit-style reading of Devanagari. For instance, राम is pronounced Rām, रचना is pronounced Racnā, वेद is pronounced Ved and नमकीन is pronounced Namkīn. The name of the script itself is pronounced Devnāgrī, not Devanāgarī.
Correct schwa deletion is also critical because the same letter sequence is pronounced two different ways in Hindi depending on the context. Failure to delete the appropriate schwas can then change the meaning. For instance, the letter sequence 'रक' is pronounced differently in हरकत and सरकना. Similarly, the sequence धड़कने in दिल धड़कने लगा and in दिल की धड़कनें is identical prior to the nasalisation in the second usage. However, it is pronounced dhaṛak.ne in the first and dhaṛ.kanẽ in the second.
While native speakers pronounce the sequences differently in different contexts, non-native speakers and voice-synthesis software can make them "sound very unnatural", making it "extremely difficult for the listener" to grasp the intended meaning.

Other Indo-Aryan languages

Different Indo-Aryan languages can differ in how they apply schwa deletion. For instance, medial schwas from Sanskrit-origin words are often retained in Bengali even if they are deleted in Hindi. An example of this is रचना/রচনা which is pronounced racanā in Sanskrit, racnā in Hindi and rôcona in Bengali. While the medial schwa is deleted in Hindi, it is retained in Bengali.
On the other hand, the final schwa in वेद /বেদ is deleted in both Hindi and Bengali.

Bengali

The Bengali equivalent for Schwa is Open-mid back rounded vowel or .
Bengali deleted this vowel at the end when not ending in a consonant cluster but sometimes retained this vowel at medial position. The consonant clusters at end of a word usually follows a Close-mid back rounded vowel or . For example, the Sanskrit word पथ corresponds to the Bengali word পথ /pɔt̪ʰ/. But the Skt. word अन्त retains the end vowel and becomes অন্ত /ɔnt̪o/ in Bengali, as it ends with a consonant cluster.
However, tatsama borrowings from Sanskrit generally retain the 'ɔˈ except in word-final positions and except in very informal speech.
That vowel in medial position are not always retained. For instance, 'কলকাতা' is pronounced as /kolkat̪a/, and not /kolɔkat̪a/..

Gujarati

Gujarati has a strong schwa deletion phenomenon, affecting both medial and final schwas. From an evolutionary perspective, the final schwas appear to have been lost prior to the medial ones.

Kashmiri

In the Dardic subbranch of Indo-Aryan, Kashmiri similarly demonstrates schwa deletion. For instance, drākṣa is the Sanskrit word for grape, but the final schwa is dropped in the Kashmiri version, which is dach.

Maithili

Maithili's schwa deletion differs from other neighbouring languages. It actually doesn't delete schwa, but shortens it., ə → ə̆ / VC_CV applies to the language. Maithili with increased influence of other languages through coming into contact with them has been showing the phenomenon of schwa deletion sometimes with words that traditionally pronounce schwas. For instance, हमरो is həməro with schwas but is pronounced həmᵊro. That is akin to the neighbouring Bhojpuri in which हमरा is pronounced həmrā rather than həmərā from the deletion of a medial schwa.

Marathi

In Marathi, the schwa at the end of the Sanskrit stems is retained in such cases as a few tatsama words.
The medial schwa is retained in most of the words. Marathi with increased influence of other languages through coming into contact with them has been showing the phenomenon of schwa deletion sometimes with words that traditionally pronounce schwas like रंग, बंद, गुण, गोड, मार्ग, etc.

Nepali

Nepali orthography is comparatively more phonetic than Hindi when it comes to schwa retention. Schwas are often retained within the words unless deletion is signaled by the use of a halanta. सुलोचना is pronounced sulocnaa by Hindi speakers while sulocanaa by Nepali speakers. However, उसको is not pronounced as *usako, rather as usko. Similarly, रामले as raamle as opposed to *raamale
The following rules can be followed to figure out whether or not Nepali words retain the final schwa in a word.
1) Schwa is retained if the final syllable is a conjunct consonant. अन्त, सम्बन्ध, श्रेष्ठ Exceptions: रङ्ग conjuncts such as ञ्‍‍‍ज ञ्‍च in मञ्‍च गञ्‍‍‍ज and occasionally the last name पन्त
2) For any verb form the final schwa is always retained unless the schwa cancelling halanta is present. हुन्छ, भएर, गएछ but छन्, गइन्. Meanings may change with the wrong orthography: गइन= she didn't go VS गइन् = she went
3) Adverbs, onomatopoeia and postpositions usually maintain the schwa and if they don't, halanta is acquired: अब, तिर, आज सिम्सिम् झन्
4) Few exceptional nouns retain the schwa such as: दुख, सुख
Note: Schwas are often retained in music and poetry to facilitate singing and recitation.

Odia

, declared the sixth classical language of India, retains the schwa in its pronunciation. Both medial and final schwas are retained.

Punjabi

Punjabi has broad schwa deletion rules: several base word forms drop schwas in the plural form as well as with instrumental and locative suffixes.

Common transcription and diction issues

Since Devanagari does not provide indications of where schwas should be deleted, it is common for non-native learners/speakers of Hindi, who are otherwise familiar with Devanagari and Sanskrit, to make incorrect pronunciations of words in Hindustani and other modern Indo-Aryan languages. Similarly, systems that automate transliteration from Devanagari to Latin script by hardcoding implicit schwas in every consonant often indicate the written form rather than the pronunciation. That becomes evident when English words are transliterated into Devanagari by Hindi-speakers and then transliterated back into English by manual or automated processes that do not account for Hindi's schwa deletion rules. For instance, the word English may be written by Hindi speakers as इंगलिश which may be transliterated back to Ingalisha by automated systems, but schwa deletion would result in इंगलिश being correctly pronounced as Inglish by native Hindi-speakers.
Some examples are shown below:
Word in Devanagari and meaningPronunciation in Hindi Pronunciation without schwa syncopeComments
लपट ləpəṭləpəṭəThe final schwa is deleted
लपटें ləpṭeṅləpəṭeṅThe medial schwa, ləpəṭ, which was retained in लपट, is deleted in लपटें
समझ səməjhsəməjhəThe final schwa is deleted
समझा səmjhāsəməjhāThe medial vowel also is deleted here, which it wasn't in समझ
भारत bhārətbhārətəFinal schwa is deleted
भारतीय bhārtīybhārətīyəBoth the medial and final schwa are deleted, although the final schwa is sometimes faintly pronounced due to the 'y' glide; when pronounced without this, the word sounds close to 'bhārtī'
देवनागरी devnāgrīdevənāgərīTwo medial schwas are deleted
इंगलिश inglishingəlishəMedial and final schwas are deleted
विमला vimlāviməlāMedial schwa is deleted
सुलोचना sulochnāsulochənāMedial schwa is deleted

Vowel nasalisation

With some words that contain /n/ or /m/ consonants separated from succeeding consonants by schwas, the schwa deletion process has the effect of nasalising any preceding vowels. Here are some examples in Hindustani: