|Sound change and alternation|
Sandhi (Sanskrit: सन्धि sandhi [sɐndʱi], "joining") is a cover term for a wide variety of sound changes that occur at morpheme or word boundaries. Examples include fusion of sounds across word boundaries and the alteration of one sound depending on nearby sounds or the grammatical function of the adjacent words. Sandhi belongs to morphophonology.
Sandhi occurs in many languages, particularly in the phonology of Indian languages (especially Sanskrit, Tamil, Sinhala, Telugu, Marathi, Hindi, Pali, Kannada, Bengali, Assamese, Malayalam). Many dialects of British English show linking and intrusive R.
A subset of sandhi called tone sandhi more specifically refers to tone changes between words and syllables. This is a common feature of many tonal languages such as Mandarin Chinese.
Sandhi can be either
It may be extremely common in speech, but sandhi (especially external) is typically ignored in spelling, as is the case in English (exceptions: the distinction between a and an; the prefixes syn-, in-, en-, and con-). Sandhi is, however, reflected in the orthography of Sanskrit, Sinhala, Telugu, Marathi, Pali and some other Indian languages, as with Italian in the case of compound words with lexicalised syntactic gemination.
External sandhi effects can sometimes become morphologised (apply only in certain morphological and syntactic environments) as in Tamil and, over time, turn into consonant mutations.
Most tonal languages have tone sandhi in which the tones of words alter according to certain rules. An example is the behavior of Mandarin Chinese; in isolation, tone 3 is often pronounced as a falling-rising tone. When a tone 3 occurs before another tone 3, however, it changes into tone 2 (a rising tone), and when it occurs before any of the other tones, it is pronounced as a low falling tone with no rise at the end.
An example occurs in the common greeting 你好 nǐ hǎo (with two words containing underlying tone 3), which is normally pronounced ní hǎo. The first word is pronounced with tone 2, but the second is unaffected.
Main articles: Breton mutations, Cornish grammar § Initial consonant mutation, Welsh morphology § Initial consonant mutation, Irish initial mutations, Manx language § Initial consonant mutations, and Scottish Gaelic phonology § Lenition and spelling
In Celtic languages, the consonant mutation sees the initial consonant of a word to change according to its morphological or syntactic environment. Following are some examples from Breton, Irish, Scottish Gaelic, and Welsh:
|ar wreg vras||y wraig fawr||an bhean mhór||a' bhean mhòr||the big woman|
|e gazh||ei gath||a chat||a chat||his cat|
|he c'hazh||ei chath||a cat||a cat||her cat|
|o c'hazh||eu cath||a gcat||an cat||their cat|
The French liaison, in which a word-final consonant that is normally silent when occurring at the end of a phrase or before another consonant, is pronounced as if part of the next word when followed by a vowel, can be considered a form of external sandhi. For example, deux frères (two brothers) is pronounced /dø fʁɛʁ/ with a silent ⟨x⟩, and quatre hommes (four men) is pronounced /katʁ ɔm/, but deux hommes (two men) is pronounced /dø‿zɔm/.
In Japanese phonology, sandhi is primarily exhibited in rendaku (consonant mutation from unvoiced to voiced when not word-initial, in some contexts) and conversion of つ or く (tsu, ku) to a geminate consonant (orthographically, the sokuon っ), both of which are reflected in spelling – indeed, the っ symbol for gemination is morphosyntactically derived from つ, and voicing is indicated by adding two dots as in か／が ka, ga, making the relation clear. It also occurs much less often in renjō (連声), where, most commonly, a terminal /n/ on one morpheme results in an /n/ (or /m/) being added to the start of the next morpheme, as in 天皇: てん ＋ おう → てんのう (ten + ō = tennō); that is also shown in the spelling (the kanji do not change, but the kana, which specify pronunciation, change).
Korean has sandhi which occurs in the final consonant or consonant cluster, such that a morpheme can an 2 pronunciations depending on whether or not is is proceeded by a vowel. For example, the root "읽" /iɾ/, meaning read, sounds like /iɾk/ before vowels, such as in, 읽으세요 /iɾkɯse̞jo/, meaning please read. Some roots can also aspirate following consonants, denoted by the letter ㅎ (hieut) in the final consonant. This causes "다" /tɐ/ to become /tʰɐ/ in 않다 /ɐntʰɐ/ (to be not).