Internal Consonant Sandhi
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- General Rules
- Aspirated Letters
- Letters from cavarga
- Retroflex letters
- Final n and m
- Final s
- Special Rules
This page covers the rules of internal consonant sandhi. Internal consonant sandhi acts within a single word. Any rule in which the first letter is a consonant is considered a consonant sandhi rule. Some of the rules have charts, which you can see at the bottom of the page.
As far as I am aware, this page contains every rule of internal consonant sandhi. Pre-Classical works don't always conform to these rules.
Internal and external consonant sandhi
The internal consonant sandhi rules and external consonant sandhi rules have many rules in common. The best way to think about the rules on this page is as "exceptions" to the normal external consonant sandhi rules. So, when you apply consonant sandhi, you should first check for the exceptions mentioned on this page; and if there aren't any that apply, you should use the external consonant sandhi rules.
No sandhi near certain letters
When the second letter letter is a vowel, a nasal, or a semivowel, no sandhi change of any kind will occur, with only a few exceptions.
Here are some examples of the general rule:
वच् + अन्ति → वचन्तिvac + anti → vacanti
वच् + मि → वच्मिvac + mi → vacmi
वाच् + य → वाच्यvāc + ya → vācya
वच् + ति → वक्तिvac + ti → vakti
Assume that all rules follow this principle. Those that do not will be clearly labeled.
These rules apply to the first letter.
Aspirated letters become unaspirated.
रुन्ध् + ध्वे → रुन्द्ध्वेrundh + dhve → runddhve
Exceptions for -h
h is treated like gh when either of these things is true:
- The second letter is s
- The h both ends a root that starts with d and is in front of t, th, or dh.
लेह् + सि → लेक् + सि → लेक्षिleh + si → lek + si → lekṣi
दह् + त → दग्धdah + ta → dagdha
दिह् + ध्वे → दिग्ध्वेdih + dhve → digdhve
In other roots, h does all three of these peculiar things:
- changes t, th, and dh — if they follow the h — into ḍh
- lengthens the vowel in front of it, if possible
मुह् + त → मूढmuh + ta → mūḍha
लिह् + त → लीढlih + ta → līḍha
ऊह् + त → ऊढūh + ta → ūḍha
Four exceptions are snih, muh, nah and dṛh.
नह् + त → नद्धnah + ta → naddha
दृह् + त → दृढdṛh + ta → dṛḍha
Moving the aspirate backward
A piece's first letter will become aspirated if all of these things are true:
- The piece starts with g, d, or b.
- The piece ends with a voiced aspirate consonant (including h).
- The aspirated sound at the end has been removed due to sandhi.
- The first sound after the piece is bh, s, or dhv.
The fourth requirement is for internal sandhi only. The other three are the same as in external consonant sandhi.
अ + बुध् + ध्वम् → अभुद्ध्वम्a + budh + dhvam → abhuddhvam
Moving the aspirate forward
t- and th-, when they are the second letter, become dh-.
बुध् + त → बुद्धbudh + ta → buddha
रुन्ध् + थः → रुन्द्धःrundh + thaḥ → runddhaḥ
दुह् + त → दुग्धduh + ta → dugdha
One exception to this rule is the root dhā, which becomes dhat in this situation.
Letters from cavarga
By the external sandhi rules, c always reduces to k. But j is more irregular. It usually becomes k, but it can also become ṭ or ṣ.
युज् + त → युक्तyuj + ta → yukta
राज् + त्र → राष्ट्रrāj + tra → rāṣṭra
मृज् + हि → मृड्ढिmṛj + hi → mṛḍḍhi
A final ś changes in these ways:
- In front of t or th, it becomes ṣ and shifts the letter that follows it to ṭavarga.
- In front of the s of a verb suffix, it becomes k.
द्रश् + स्य + सि → द्रक्ष्यसिdraś + sya + si → drakṣyasi
prach is treated like praś. In external sandhi and ātmanepada, it becomes praṭ.
पृछ् + त → पृष् + त → पृष्टpṛch + ta → pṛṣ + ta → pṛṣṭa
Changing n- to ñ-
Final c and j change n- to ñ-.
याच् + ना → याच्ञyāc + nā → yācñā
यज् + न → यज्ञyaj + na → yajña
A retroflex letter, if followed by a tavarga letter, shifts it to ṭavarga.
इष् + त → इष्टiṣ + ta → iṣṭa
विश् + त → विष् + त → विष्टviś + ta → viṣ + ta → viṣṭa
ṣ becomes k when followed by s.
द्वेष् + सि → द्वेक्षिdveṣ + si → dvekṣi
Final n and m
Final n becomes the anusvāra if both of these things are true:
- The n is the last letter of a verb root
- The initial letter is s
जिघान् + स + ति → जिघांसतिjighān + sa + ti → jighāṃsati
मीमान् + स + ति → मीमांसतिmīmān + sa + ti → mīmāṃsati
Final m becomes n in front of v.
जगम् + वत् → जगन्वत्jagam + vat → jaganvat
A final s changes in one of two ways:
- s changes to t
- s disappears
s changes to t
The s in vas and ghas becomes t when in front of the s of a verb suffix.
वस् + स्य + ति → वत्स्यतिvas + sya + ti → vatsyati
जिघस् + स + ति → जिघत्सतिjighas + sa + ti → jighatsati
s also becomes t in some parts of the reduplicated perfect.
s disappears when in front of d or dh.
शास् + धि → शाधिśās + dhi → śādhi
These rules will always apply, with only a few extremely rare exceptions. The exceptions can be counted on one hand.
n → ṇ
- ṛ, ṝ, r, or ṣ,
- if followed only by vowels, kavarga, pavarga, h, v, y, or the anusvāra,
- changes n to ṇ
- if the n is followed by either a a vowel or these letters: m, y, v, n.
- If there is another n after the first one, then they change together.
The idea is this. The four sounds in the first line will leave the tongue in the retroflex position. The tongue stays there for the vowels, kavarga, pavarga, and some other sounds, and it will stay there unless any other sound is spoken. If nothing causes the tongue to move, then the third line comes into play.
अरुन → अरुणaruna → aruṇa
अर्जुन → अर्जुनarjuna → arjuna
रामायन → रामायणrāmāyana → rāmāyaṇa
कुर्वन्ति → कुर्वन्तिkurvanti → kurvanti
ब्रह्मन् → ब्रह्मन्brahman → brahman
ब्राह्मन → ब्राह्मणbrāhmana → brāhmaṇa
s → ṣ
- k, r, and any vowel except a/ā,
- in spite of intervening anusvāra or visarga,
- changes s to ṣ
- as long as the s is not final and not followed by r.
हविसा → हविषाhavisā → haviṣā
तिस्थ → तिष्ठtistha → tiṣṭha
Exceptions are hiṃs and puṃs.
|Change||Cause||Condition 1||Condition 2|
|n → ṇ||Any retroflex sound that is not a stop consonant (ṛ, ṝ, r, ṣ)||One of these four letters appears in front of n. The two letters may be separated by any of the following: vowels, letters from kavarga and pavarga, h, y, v, or the anusvāra||n is followed by a vowel, m, y, v, or another n.|
|s → ṣ||k, r, and any vowel apart from a and ā (i, ī, u, ū, ṛ, ṝ, e, ai, o, au)||One of these ten letters appears in front of s. The two letters may be separated by a visarga or anusvāra||s is not followed by r.|