, particularly within historical linguistics
, dissimilation is a phenomenon whereby similar consonant
s or vowel
s in a word
become less similar. In English
, dissimilation is particularly common with liquid consonants
such as /r/ and /l/ when they occur in a sequence.
Dropped initial /r/ in /r..r/ sequence (r-Deletion)
When a sound occurs before another in the middle of a word in rhotic dialect
s of English
, the first tends to drop out, as in "beserk" for ''berserk,'' "suprise" for ''surprise,'' "paticular" for ''particular'', and "govenor" for ''governor'' – this does not affect the pronunciation of ''government,'' which has only one , but English ''government'' tends to be pronounced "goverment", dropping out the first n.
In English, ''r''-deletion occurs when a syllable is unstressed and /r/ may drop out altogether, as in "deteriate" for ''deteriorate'' and "tempature" for ''temperature,'' a process called haplology
. When the is found in , it may change to : "Febyuary" for ''February,'' "defibyulator" for ''defibrillator,'' though this may be due to analogy with similar words, such as ''January'' and ''calculator'' (compare ''nucular
'', which may have arisen through an analogous process).
Dissimilation of /l..l/ to /r..l/
An example where a relatively old case of phonetic dissimilation has been artificially undone in the spelling is English ''colonel
'', whose standard pronunciation is (with the r sound) in North-American English, or in RP
. It was formerly spelt ''coronel'' and is a borrowing from French ''coronnel'', which arose as a result of dissimilation from Italian ''colonnello''.
["Pronunciation Note" a]
Colonel @ Dictionary.Reference.com
Dissimilation of /r..r/ to /l..r/
* Latin peregrinus
> Old French pelegrin
(and the Italian pellegrino
) which gave rise to the English .
There are several hypotheses on the cause of dissimilation. According to John Ohala
, listeners are confused by sounds with long-distance acoustic effects. In the case of English , rhoticization
spreads across much of the word: in rapid speech, many of the vowels may sound as if they had an ''r''. It may be difficult to tell whether a word has one source of rhoticity or two. When there are two, a listener might wrongly interpret one as an acoustic effect of the other, and so mentally filter it out.
This factoring out of coarticulatory
effects has been experimentally replicated. For example, Greek ''pakhu-'' (παχυ-) "thick" derives from an earlier ''*phakhu-.'' When test subjects are asked to say the ''*phakhu-'' form in casual speech, the aspiration from both consonants pervades both syllables, making the vowels breathy
. Listeners hear a single effect, breathy voiced vowels, and attribute it to one rather than both of the consonants, as they assume the breathiness on the other syllable to be a long-distance coarticulatory effect, thus replicating the historical change in the Greek word.
If Ohala is correct, one might expect to find dissimilation in other languages with other sounds that frequently cause long-distance effects, such as nasalization
Dissimilation, like assimilation
, may involve a change in pronunciation relative to a segment that is adjacent to the affected segment or at a distance, and may involve a change relative to a preceding or a following segment. As with assimilation, anticipatory dissimilation is much more common than lag dissimilation, but unlike assimilation, most dissimilation is triggered by ''non''-contiguous segments. Also, while many kinds of assimilation have the character of a sound law
, few dissimilations do; most are in the nature of accidents that befall a particular lexical item.
Anticipatory dissimilation at a distance (by far the most common):
*''medio-diēs'' ("mid-day", i.e. "noon"; also "south") became ''merīdiēs''. Latin ''venēnum'' "poison" > Italian
''veleno''. This category includes a rare example of a systematic sound law, the dissimilation of aspirates in Greek
known as Grassmann's Law
: *''thi-thē-mi'' "I put" (with a reduplicated prefix) > Greek ''tí-thē-mi'' (τίθημι), *''phakhu'' "thick" > Greek ''pakhus'' (παχύς), *''sekhō'' "I have" > *''hekhō'' > Greek ''ékhō'' (ἔχω; cf. future *''hekh-s-ō'' > ''héksō'' ἕξω). Some apparent cases are problematic, as in English "eksetera" for ''etcetera
'', which may rather be contamination from the numerous forms in ''eks-'' (or a combination of influences), though the common misspelling ''ect''. implies dissimilation.
Anticipatory dissimilation from a contiguous segment (very rare):
* The change from fricative to stop articulation in a sequence of fricatives may belong here: German ''sechs'' (as evidenced by the spelling, the was previously a fricative
). In Sanskrit in any original sequence of two sibilants
the first became a stop (often with further developments): root ''vas''- "dress", fut. ''vas-sya''- > ''vatsya''-; *''wiś-s'' "clan" (nom.sg.) > *''viťś > *viṭṣ > viṭ'' (final clusters are simplified); *''wiś-su'' locative pl. > *''viṭṣu > vikṣu''. English ''amphitheater'' is very commonly pronounced ''ampitheater'' (though spelling pronunciation
may be either some or all of the story here). Russian конфорка 'stove burner' is from Dutch ''komfoor'' 'brazier'.
Lag dissimilation at a distance (fairly common):
* English "purple" is in medieval English as ''purpul'' and ''purpure'' (in medieval French ''porpre'') and comes from classical Latin ''purpura'' = "purple" with dissimilation of to . Latin ''rārus'' "rare" > Italian ''rado''. ''Cardamom'' is commonly pronounced ''cardamon''. In Middle English, in some words ending in -''n'' preceded by a coronal consonant the ''-n'' changed to -''m'': ''seldom, random, venom''. English ''marble'' is ultimately from Latin ''marmor''. Russian февраль 'February' is from Latin ''Februārius''.
* In Spanish, interchanges between and are common; for a list, see History of the Spanish language#Interchange of the liquids /l/ and /r/
. In Basque, dissimilation is frequent as well.
Lag dissimilation from a contiguous segment (very rare):
* Latin ''hominem'' ("man", acc.) > Old Spanish
''omne'' > ''omre'' > Spanish
* Latin ''nomine'' ("name", abl.) > ''nomre'' > Spanish ''nombre''
''chimney'' (standard) > ''chim(b)ley'' (dialectal)
*''sveboda'' "freedom" > Slovak
* In Irish
, many dialects regularly change the sequence to
When, through sound change
, elements of a grammatical paradigm start to conflate in a way that is not easily remedied through re-wording
, the forms may dissimilate. For example, in modern Korean
the vowels and are merging for many people in the capital Seoul, and concurrently the second-person pronoun 네 'you' is shifting to 니 to avoid confusion with the first-person pronoun 내 'me'.
Similarly, it appears that English ''she
,'' historically ''heo'', may have acquired its modern ''sh'' form through dissimilation from ''he'', though it is not clear whether the mechanism was idiosyncratic sound change (palatalization
) of ''heo'', or substitution of ''heo'' with the feminine demonstrative pronoun
* Assimilation (linguistics)
* Crowley, Terry. (1997) ''An Introduction to Historical Linguistics.'' 3rd edition. Oxford University Press.
(''International Encyclopedia of Linguistics'', 2nd ed.)