Why we put 'a' after each Hindu name?

Question

For example: Yog becomes Yog'a' or Krishn -> Krishna; same way Ram -> Rama

Answer 1

TL;DR: It's due to schwa deletion rule of Hindi.

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First off, it is incorrect and incomplete to write the Sanskrit or Devanāgarī word राम (Rāma) as "Rama" as commonly written by English writers on this forum and elsewhere. The table below lists the accepted Romanised transliterations of राम. Same goes for कृष्ण - "Krishna" is not recommended, while Kṛṣṇa or kRSNa is more acceptable.

IAST makes no special use of capital letters so people often capitalize proper nouns, so both rāma and Rāma are valid.

Now for ease of use, people just write 'Rama' or 'Krishna' because it's difficult to type accented letters such as ś, ṛ and even long vowels such as ā (आ) using a QWERTY keyboard. Also, when you just write 'Rama' you are actually transcribing i.e., freely converting sound from one language to another - technically it's not correct as information is lost in the process. A native English speaker might interpret 'Rama' as रम instead of राम.

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Now to your actual question: Why not write राम as Rām instead of Rāma & कृष्ण as Kṛṣṇ instead of Kṛṣṇa?

That's because, if transliterated as above it would lead to a different word altogether in Sanskrit. Rām would represent राम् and Kṛṣṇ or kRSN would mean कृष्ण्

Now if you are Hindi speaker, you probably pronounce राम as राम् and vice versa.

But in Sanskrit both are different, म् + अ (schwa) = म

So when you are transliterating (especially Sanskrit names and scripture) to Roman alphabet you need to be a little careful, use one of IAST, ITRANS or Harvard-Kyoto.

+============+=============+================+================+===============+
| Devanāgarī |    IAST     |   ITRANS 5.1   |   ITRANS 5.3   | Harvard-Kyoto |
+============+=============+================+================+===============+
| राम        | Rāma        | raama          | raama          | rAma          |
+------------+-------------+----------------+----------------+---------------+
| कृष्ण       | Kṛṣṇa       | kR^iShNa       | kR^iShNa or    | kRSNa         |
+------------+-------------+----------------+----------------+---------------+
|            |             |                | kRRiShNa       |               |
+------------+-------------+----------------+----------------+---------------+
| योग        | Yoga        | yoga           | yoga           | yoga          |
+------------+-------------+----------------+----------------+---------------+
| शिव        | Śiva        | shiva          | shiva          | ziva          |
+------------+-------------+----------------+----------------+---------------+
| महाभारत    | Mahābhārata | mahAbhArata or | mahAbhArata or | mahAbhArata   |
+------------+-------------+----------------+----------------+---------------+
|            |             | mahaabhaarata  | mahaabhaarata  |               |
+------------+-------------+----------------+----------------+---------------+
| ज्ञान        | jñāna       | GYaana/GYAna   | GYaana/GYAna   | jJAna         |
+------------+-------------+----------------+----------------+---------------+
|            |             | j~naana/j~nAna | j~naana/j~nAna |               |
+------------+-------------+----------------+----------------+---------------+
|            |             | dnyaana/dnyAna | dnyaana/dnyAna |               |
+------------+-------------+----------------+----------------+---------------+

Reference: Learning Sanskrit - Transliterating

Answer 2

References for this annswer:

• Chapter 1 of Samskrita Bharati Pravesha
• Chapter 1 of A Practical Grammar of the Sanskrit Language
• Consonants section under Devanagari transliteration wiki article

  The Devanāgarī standalone consonant letters are followed by an implicit shwa (/Ə/). In all of the transliteration systems, that /Ə/ must be represented explicitly using an 'a' or any equivalent of shwa.

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In DevaNagari languages (such as Sanskrit and Hindi), each full-form constant is a combination of half-form constant and a vowel.

i.e.

full-form constant = half-form constant + vowel

For example,

म (ma) = म् (m) + अ (a)

Hence, all words have to be ended by a vowel but not necessarily by 'a'. For example,

Vishnu (विष्णु)

Manu (मनु)

Yayati (ययाति)

Draupadi (द्रौपदी)

However, when there is no need of a vowel in pronunciation (most of the case if word referers to a Masculine noun), then we use 'a'. For example:

Raama > Rama (राम)

Bhishma (भीष्म)

Drona (द्रोण)

Raavana > Ravana (रावण)

Ganesha (गणेश)

Shiva (शिव) 1

Krishna (कृष्ण) 2

But most of the time, for simplicity we use 'a' instead of 'aa' (for example, we write Aarati (आरती) as Arati) and that should be pronounced (most of the case if word referers to a Feminine noun). For example,

Sitaa -> Sita(सीता)

Shivaa -> Shiva (शिवा) 3

Krishnaa -> Krishna (कृष्णा) 4

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Footnotes:

1 Shiva (शिव) : Masculine noun for one who is auspicious. Example: name of Lord Shiva

3 Shivaa -> Shiva (शिवा) : Feminine noun for one who is auspicious or Feminine noun for one who is consort of Shiva. Example: name of Goddess Parvati

2 Krishna (कृष्ण) : Masculine noun for one whose complexion is dark. Example: name of Lord Krishna, Arjuna 

4 Krishnaa -> Krishna (कृष्णा) : Feminine noun for one whose complexion is dark. Example: name of Draupadi 

Answer 3

In the Devanagri script (used for Sanskrit) the first alphabet / vowel is 'अ' or 'a'. If the vowel 'a' is not added to the word, the word is incomplete - Rama without 'a' i.e Ram would be in Devanagri script become 'राम्' and not 'राम'. Similarly for Shiva, Krishna, etc.

The second alphabet / vowel is 'आ' or 'aa'. Whenever 'aa' is added to a word it denotes the feminine. Thus 'कृष्णा' is the name of Draupadi and not Sri Hari 'कृष्ण'.

Hope this clarifies your query.