Sandhi (सन्धि, literally "joining") is the system of rules by which adjacent sounds in Sanskrit alter to produce a smooth, euphonic flow. operates both internally within a single word and externally between two words in a sentence. Mastery of is essential for reading Sanskrit because words on the page are often glued together and must be analytically separated to be understood.
Why Exists
Spoken Sanskrit was prized for its melodic quality. When two sounds collided awkwardly — a vowel ending one word and a vowel beginning the next, for example — the language smoothed the transition by combining or modifying them. Pāṇini codified these processes with great precision, and his rules remain the standard description today.
There are three main families of : vowel (svara-sandhi), consonant (vyañjana-sandhi), and visarga (visarga-sandhi).
Vowel ()
When a vowel ends one word and a vowel begins the next, several rules apply.
Same-vowel merging. Two like vowels combine into a single long vowel:
na + asti → nāsti (न + अस्ति → नास्ति, "there is not").
Guna substitution. When a or ā meets i, u, or ṛ, the result is the corresponding guṇa vowel — e, o, or ar:
sura + indra → surendra (सुर + इन्द्र → सुरेन्द्र, "lord of gods").
Vriddhi substitution. When a or ā meets e or o, the result is ai or au:
mahā + aiśvarya → mahaiśvarya (महा + ऐश्वर्य → महैश्वर्य).
Semivowel substitution. When i, u, or ṛ meets a dissimilar vowel, the first becomes its corresponding semivowel:
iti + uktvā → ityuktvā (इति + उक्त्वा → इत्युक्त्वा).
Consonant ()
Consonants too modify in contact. A few characteristic patterns:
Final t-modification. A final t often assimilates to the following consonant. tat + ca → tac ca; tat + jayati → taj jayati; tat + na → tan na.
Nasal assimilation. A nasal at a word boundary often takes on the place of articulation of the following consonant.
Voicing. A voiceless consonant at the end of one word followed by a voiced consonant at the start of the next often becomes voiced:
vāk + īśa → vāgīśa (वाक् + ईश → वागीश, "lord of speech").
Visarga ()
The visarga (ः) is the breathy ḥ sound that appears at the end of many Sanskrit words. Its behaviour in is intricate because it transforms differently depending on the preceding vowel and the following sound.
- Before a: rāmaḥ + asti → rāmo'sti (रामः + अस्ति → रामोऽस्ति). The visarga becomes u which then merges with the preceding a to form o; the following a is replaced by an avagraha (ऽ).
- Before voiced consonants: visarga often becomes o.
- Before k or p: visarga remains as a voiceless aspirate or becomes ḥ.
- Before sibilants: visarga assimilates to the sibilant — namaḥ + śivāya → namaśśivāya (नमः + शिवाय → नमश्शिवाय, often written नमः शिवाय in printed texts).
Reading and Writing
In printed Sanskrit, is typically applied throughout a verse, with all words run together according to the rules. Beginners learn to dissolve by reversing the process (called vigraha) so the underlying words can be identified. This skill is the gateway to reading the Mahābhārata, the Gītā, and the great Upaniṣads in their original form.
reveals Sanskrit's love of harmony: nothing in the language is allowed to clash if it can be made to flow.