सन्धिः — what happens when words meet

Sandhi is not decoration

6.1.72

A beginner meets sandhi as an obstacle: the text has run all the words together and now they have to be prised apart. That is the right practical problem, but the wrong picture of what is happening.

संहितायाम्The condition every sandhi rule stands under

— 6.1.72. Every rule in this chapter is governed by it, and it means in close juncture: when the sounds are spoken continuously, without a pause between them.

So sandhi is not something done to a text. It is what continuous speech already does, written down honestly. English does it too — "cupboard" is not pronounced cup-board and has not been for centuries; the difference is that English spelling froze and Sanskrit's did not.

Read a rule the way Pāṇini writes one

Every sandhi rule names up to four things, and it names them by case alone:

ṣaṣṭhī — what is replaced, the स्थानी ( )
prathamā — what replaces it, the आदेशः
saptamī — what must follow, the निमित्तम् ( )
pañcamī — what must precede ( )

Nothing else marks the roles. Once you can read cases you can read a sandhi rule without being told what it means — and that is worth more than memorising its effect.

Everything below is read this way. The role labels on each rule card are not this page's interpretation; they are taken from the sūtra's own padaccheda, case by case. Where a role is not stated it is inherited, and the card says from which sūtra.

स्वरसन्धिः

Vowel meets vowel

five rules

The five rules, and nothing else

Which rule fires depends on nothing but the two vowels. Learn to ask the two questions in order — are they the same kind? then what kind is the first one? — and the choice is forced.

The table, read as a row against a column

Row = the vowel a word ends in. Column = the vowel the next begins with. Every filled cell holds a real example from the corpus, placed there by its own two vowels. A hatched cell means the corpus states no example there — not that nothing happens.

Watch one fire

The interesting part of a vowel-sandhi rule is invisible: the अ in देव is not written anywhere, and the ए that replaces it is a mātrā hanging off व. So the animation opens the akṣaras up before it substitutes.

Which vowel is actually replaced is not obvious, and Pāṇini says so. Under 6.1.84 — एकः पूर्वपरयोः — a single sound replaces both the final and the following vowel. Rules inside that domain (savarṇa-dīrgha, guṇa, vṛddhi) consume the second vowel; rules outside it (yaṇ, ayādi) replace only the first and leave the second standing. Compare भू + उदयः → भ् + ऊ + उ + दयः → भूदयः with दधि + अत्र → दध् + इ + अत्र → दध्यत्र.

व्यञ्जनसन्धिः

Consonant meets anything

assimilation

विसर्गसन्धिः

The visarga

one source

रुँOne source, four surfaces

A primer teaches the visarga table as a list of outcomes to memorise. The Aṣṭādhyāyī does not. 8.2.66 turns the final स् of रामस् into रुँ, and everything after that is one rule or another reacting to what comes next.

Below are four derivations of the same word, differing only in the word that follows it. Each is taken from the corpus step by step, and each step names the rules that fired.

This is the argument for learning the Aṣṭādhyāyī's order rather than a primer's. Four facts that look unrelated in a table turn out to be one rule and its consequences. The table is not wrong — it is just the shadow of something simpler.

The exceptions

Coverage

Where every example on this page comes from. The rules, their roles and their worked examples are taken from the corpus's own सूत्रार्थः layer — the same text the reading view shows under the depth dial — and the junction of each pair was peeled apart mechanically rather than by eye. Nothing here was typed from memory. The reference version carries all rules with every alternative example.

Check yourself

अभ्यासः

Six questions. Each comes down to identifying the two sounds that met.