In
historical linguistics, a number of traditional terms designate types of phonetic change, either by nature or result. A number of such types are often (or usually) sporadic, that is, more or less accidents that happen to a specific form. Others affect a whole phonological system. Sound changes that affect a whole phonological system are also classified according to how they affect the overall shape of the system; see
phonological change. •
Assimilation: One sound becomes more like another, or (much more rarely) two sounds become more like each other. Example: in Latin the prefix *
kom- becomes
con- before an
apical stop () or :
contactus "touched",
condere "to found, establish",
connūbium "legal marriage". The great majority of assimilations take place between contiguous segments, and the great majority involve the earlier sound becoming more like the later one (e.g. in
connūbium, m- + n becomes
-nn- rather than
-mm-). Assimilation between contiguous segments are (
diachronically speaking) exceptionless sound laws rather than sporadic, isolated changes. •
Dissimilation: The opposite of assimilation. One sound becomes less like another, or (much more rarely) two sounds become less like each other. Examples: Classical Latin
quīnque "five" > Vulgar Latin *
kinkʷe (whence French
cinq, Italian
cinque, etc.);
Old Spanish omne "man" > Spanish
hombre. The great majority of dissimilations involve segments that are contiguous, but, as with assimilations, the great majority involve an earlier sound changing with reference to a later one. Dissimilation is usually a sporadic phenomenon, but
Grassmann's Law (in Sanskrit and Greek) exemplifies a systematic dissimilation. If the change of a sequence of fricatives such that one becomes a stop is dissimilation, then such changes as
Proto-Germanic *hs to (spelled
x) in English would count as a regular sound law: PGmc. *
sehs "six" >
Old English siex, etc. •
Metathesis: Two sounds switch places. Example: Old English
thridda became Middle English
third. Most such changes are sporadic, but occasionally a sound law is involved, as Romance *
tl > Spanish
ld, thus *
kapitlu, *titlu "chapter (of a cathedral)", "
tittle" > Spanish
cabildo, tilde. Metathesis can take place between non-contiguous segments, as Greek
amélgō "I milk" > Modern Greek
armégō. •
Lenition: "Weakening" of a consonant from one that takes more effort to pronounce (and more constriction in the vocal tract) to one that takes less, e.g. a
stop consonant becoming an
affricate or
fricative. •
Fortition: the opposite of lenition, "strengthening" a consonant, e.g. an
approximant becoming an affricate or fricative. •
Reduction: Whereas the weakening of consonants is called
lenition, the weakening of vowels is called
reduction. For example, in most varieties of English, unstressed vowels often reduce to a
schwa, such as the two a's in
arena. •
Tonogenesis: Syllables come to have distinctive
pitch contours. •
Sandhi: Conditioned changes that take place at word-boundaries but not elsewhere. It can be
morpheme-specific, as in the loss of the vowel in the enclitic forms of English
is , with subsequent change of to adjacent to a voiceless consonant ''Frank's not here
. Or a small class of elements, such as the assimilation of the of English the, this
and that
to a preceding (including the of and
when the is elided) or : all the
often , in the
often , and so on. As in these examples, such features are rarely indicated in standard orthography. In a striking exception, Sanskrit orthography reflects a wide variety of such features; thus, tat
"that" is written tat
, tac
, taj
, tad
, or tan'' depending on what the first sound of the next word is. These are all assimilations, but medial sequences do not assimilate the same way. •
Haplology: The loss of a syllable when an adjacent syllable is similar or (rarely) identical. Example: Old English
Englaland became Modern English
England, or the common pronunciation of
probably as . This change usually affects commonly used words. The word
haplology itself is sometimes jokingly pronounced
haplogy. •
Elision,
aphaeresis,
syncope, and
apocope: All are losses of sounds. Elision is the loss of unstressed sounds, aphaeresis the loss of initial sounds, syncope is the loss of medial sounds, and apocope is the loss of final sounds. • Elision examples: in the southeastern United States, unstressed schwas tend to drop, so "American" is not but . Standard English is
possum English
humble; in Slavic an -l- intrudes between a labial and a following yod, as *
zemya "land" > Russian
zemlya (земля). Most commonly, epenthesis is in the nature of a "transitional" consonant, but vowels may be epenthetic: non-standard English
film in two syllables,
athlete in three. Epenthesis can be regular, as when the Indo-European "tool" suffix *-
tlom everywhere becomes Latin -
culum (so
speculum "mirror" 3-tlom
). Some scholars reserve the term epenthesis
for "intrusive" vowels and use excrescence'' for intrusive consonants. •
Prothesis: The addition of a sound at the beginning of a word. Example: word-initial + stop clusters in Latin gained a preceding in Old Spanish and Old French; hence, the Spanish word for "state" is
estado, deriving from Latin
status. •
Nasalization: Vowels followed by nasal consonants can become nasalized. If the nasal consonant is lost but the vowel retains its nasalized pronunciation, nasalization becomes
phonemic, that is, distinctive. Example: French "-in" words used to be pronounced , but are now pronounced , and the is no longer pronounced (except in cases of
liaison). ==Examples of specific sound changes in various languages==