Explanation
Sandhi denotes rule-governed sound changes at boundaries between adjacent linguistic units. Sounds may assimilate, disappear, be inserted, or alter their articulation because words and morphemes do not simply follow one another as isolated objects in speech. External sandhi operates between words and internal sandhi within complex forms, although classification depends on the linguistic tradition being described. The term does not mean arbitrary indistinct pronunciation or a single historical change, but boundary processes that can be systematised synchronically or diachronically. The conceptual movement leaves the citation form, observes the contact zone between two units, and reconstructs the conditions under which their sounds reshape one another.
Movement of thought
1. Two linguistic units are first identified through their separately recoverable sound forms. 2. Their immediate combination creates a phonological or phonetic boundary condition. 3. A language-specific rule changes, deletes, adds, or fuses sounds at that boundary. 4. A counter-test separates productive or historically regular alternation from a slip and accidental reduction. 5. Comparison of base form, context, and outcome makes the hidden boundary rule reconstructable.
Scientific use case
Phonology, historical linguistics, and speech technology model sandhi rules from paradigmatic and acoustic evidence. Automatic recognition requires metadata for variety, speaking rate, boundary type, and possible optionality.
Example
In a documented language variety, a word-final nasal regularly assimilates in place before a following labial sound. It retains its base form before members of other sound classes.
Counterexample
A sound swallowed once through fatigue is not sandhi unless a recurrent contextual condition can be shown. Mere spelling variation likewise establishes no sandhi without an associated sound process.
Distinction
Distinguish sandhi from free phonetic reduction, purely orthographic fusion, permanent sound change, and assimilation as a broader process. Sandhi locates regular changes at morphological or syntactic boundaries.
Effect on thought and perception
Sandhi makes continuous speech articulatorily connected and shapes rhythm and word recognition. It may conceal familiar words from learners while revealing how linguistic boundaries are organised.
Resonance
At a boundary, sounds do not remain untouched: one takes up the movement of another. Language appears as a current in which proximity helps form each unit.
Cite this entry
Reich, Michael (Hrsg./ed.): „Sandhi“. Atlas der Sprache, AT-119-006. ATLAS 260, data model 1.6.0. https://atlasoflanguage.com/concept/AT-119-006The address remains stable; editorial content may evolve. Editorial reading state: 2026-10-15. Include your access date for precise references.
Historical background
Chapter IV relates Irish initial changes to preceding material and grammatical function. Sapir's account distinguishes earlier phonetic conditioning from later grammatical patterns. This is a comparison for sandhi rather than proof that all initial mutations share one category or that the Sanskrit term's history has been established.
How conceptual history changes the analysis
Examine current phonetic environment separately from grammatical dependency. An earlier condition may disappear while its pattern survives.
References for the historical section
- Edward Sapir, Language (1921), Gutenberg transcription carrying later printing information · Language IV: Irish initial changes and preceding-word relations
Selected witness, not a complete genealogy or first English attestation. Contemporary Atlas comparisons are editorial interpretations. Sapir transcription contains later printing information. Historical language examples are attributed reports, not independently verified contemporary descriptions; racial classifications and cultural hierarchies are not adopted.