View source for Dissimilation

{{Short description|Linguistic phenomenon where sounds diverge}}
{{for|the metabolic breakdown of molecules|Catabolism}}
{{more citations needed|date=March 2021}}
{{Sound change}}
{{IPA notice}}
In [[phonology]], particularly within [[historical linguistics]], '''dissimilation''' is a phenomenon whereby similar [[consonant]]s or [[vowel]]s in a [[word (linguistics)|word]] become less similar or elided. In [[English language|English]], dissimilation is particularly common with [[liquid consonants]] such as {{IPA|/r/}} and {{IPA|/l/}} when they occur in a sequence. The phenomenon is often credited to ''[[horror aequi]]'', the principle that language users avoid repetition of identical linguistic structures.

==Examples==
=== Dropped initial /r/ in /r..r/ sequence (r-deletion) ===
When an {{IPA|/r/}} sound occurs along with another in the middle of a word in [[rhotic dialect]]s of English, the most weakly-stressed tends to drop out, as in "{{not a typo|beserk}}" for ''berserk'', "{{not a typo|suprise}}" for ''surprise'', "{{not a typo|paticular}}" for ''particular'', and "{{not a typo|govenor}}" for ''governor''.<ref>"{{IPA|/r/}} Dissimilation" in [https://linguistlist.org/issues/17/17-2235/ The Linguist List, 3 Aug 2006].</ref> This does not affect the pronunciation of ''government'', which has only one {{IPA|/r/}}, but English ''government'' tends to be pronounced "{{not a typo|goverment}}", dropping the first ''n''. Nor does this phenomenon affect the unstressed syllable in words like ''surfer'' or ''brother'', since they come at the end of the word.

In English, ''r''-deletion occurs when a syllable is unstressed and {{IPA|/r/}} may drop out altogether, as in "{{not a typo|deteriate}}" for ''deteriorate'' and "{{not a typo|tempature}}" for ''temperature'', a process called [[haplology]]. When the {{IPA|/r/}} is found in {{IPA|/bru/}}, it may change to {{IPA|/j/}}—{{Abbr|e.g.|For example}} ''February'' → ''{{not a typo|Febyuary}}'',<ref>{{cite web |last=Nunberg |first=Geoffrey |date=October 2, 2002 |title=Going Nucular |url=http://people.ischool.berkeley.edu/~nunberg/nucular.html |access-date=2008-09-14}}</ref> which has been explained by [[Phonotactics|phonotactic]] factors or alternatively by [[Morphology (linguistics)|morphological]] analogy with more common sequences such as ''January''.{{Original research inline|date=June 2025}} {{Abbr|Cf.|Compare to}} ''[[nucular]]'', which may have arisen through an analogous process.<ref>{{cite web|last=Pinker|first=Steven|date=Oct 4, 2008|title=Everything You Heard Is Wrong|url=http://pinker.wjh.harvard.edu/articles/media/2008_Palin_language.html|access-date=2013-11-15|archive-url=https://web.archive.org/web/20150519065040/http://pinker.wjh.harvard.edu/articles/media/2008_Palin_language.html|archive-date=2015-05-19}}</ref><ref>{{cite web|last=Zwicky|first=Arnold|date=March 21, 2005|title=Axe a stupid question|url=http://itre.cis.upenn.edu/~myl/languagelog/archives/001999.html|access-date=2008-09-14}}</ref>

''r''-deletion is not universally applied in regard to primary and tertiary stress. For example, ''forward'' is typically affected (''{{not a typo|foward}}''), but ''foreword'' and ''Harvard'' are not. ''Foreword'''s lack of ''r''-deletion may be due to its lower-frequency usage, but this inconsistency may also indicate that the process is still in flux and not yet fully established.

=== Dissimilation of /l..l/ to /r..l/ ===
An example of a relatively old case of phonetic dissimilation artificially undone in the spelling is English ''{{linktext|colonel}}'', whose standard pronunciation is {{IPA|[ˈkɝnəl]}} (with the r sound) in North-American English or {{IPA|[ˈkɜːnəl]}} in [[Received Pronunciation|RP]]. It was formerly spelt ''coronel'' and is a borrowing from French {{wikt-lang|frm|co'''r'''onne'''l'''}}, which arose as a result of dissimilation from Italian {{wikt-lang|it|co'''l'''onne'''ll'''o}}.<ref>"Pronunciation Note" at [http://dictionary.reference.com/browse/colonel Colonel @ Dictionary.Reference.com].</ref>

=== Dissimilation of /r..r/ to /l..r/ ===
* Latin {{wikt-lang|la|peregrinus|pe'''r'''eg'''r'''inus}} > Old French {{wikt-lang|fro|pelegrin|pe'''l'''eg'''r'''in}} (and the Italian {{wikt-lang|it|pellegrino|pe'''ll'''eg'''r'''ino}} and Sicilian {{wikt-lang|scn|piḍḍigrinu|pi'''ḍḍ'''ig'''r'''inu}}), which gave rise to the English ''{{linktext|pilgrim}}''.{{citation needed|date=March 2021}}

==Causes==
{{unreferenced section|date=March 2021}}
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 {{IPA|/r/}}, [[Rhotacism (sound change)#Other languages|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 [[coarticulation|coarticulatory]] effects has been experimentally replicated. For example, Greek {{Transliteration|el|pakhu-}} ({{lang|el|παχυ-}}) {{gloss|thick}} derives from an earlier *{{Transliteration|el|phakhu-}}. When test subjects are asked to say the *{{Transliteration|el|phakhu-}} form in casual speech, the aspiration from both consonants pervades both syllables, making the vowels [[breathy voice|breathy]].{{Citation needed|date=May 2008}} 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 is a long-distance coarticulatory effect, thus replicating the historical change in the Greek word.{{Citation needed|date=May 2008}}

If Ohala is correct, one might expect to find dissimilation in other languages with sounds that frequently cause long-distance effects, such as [[nasalization]] and [[pharyngealization]].

==Types==
{{unreferenced section|date=March 2021}}
Dissimilation, like [[assimilation (phonetics)|assimilation]], may involve a change in pronunciation relative to a segment 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, {{em|anticipatory}} dissimilation is much more common than {{em|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 accidents that befall a particular lexical item.

===Anticipatory dissimilation===
Anticipatory dissimilation at a distance (by far the most common):
* [[Latin]] *{{lang|la|medio-diēs}} ({{gloss|mid-day}}, i.e. "noon"; also "south") became {{lang|la|merīdiēs}}. Latin {{lang|la|venēnum}} "poison" > [[Italian language|Italian]] {{lang|it|veleno}}. This category includes a rare example of a systematic sound law, the dissimilation of aspirates in [[Greek language|Greek]] and [[Sanskrit]] known as [[Grassmann's Law]]: *''thi-thē-mi'' {{gloss|I put}} (with a reduplicated prefix) > Greek {{Transliteration|el|tí-thē-mi}} ({{lang|el|τίθημι}}), *''phakhu'' {{gloss|thick}} > Greek {{Transliteration|el|pakhus}} ({{lang|el|παχύς}}), *''sekhō'' {{gloss|I have}} > *''hekhō'' > Greek {{Transliteration|el|ékhō}} ({{lang|el|ἔχω}}; cf. future *''hekh-s-ō'' > {{Transliteration|el|héksō}} {{lang|el|ἕξω}}). Some apparent cases are problematic, as in English "eksetera" for ''[[etcetera]]'', which may 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 {{lang|de|sechs}} {{IPA|/zeks/}} (as evidenced by the spelling, the {{IPA|/k/}} was previously a [[fricative]]). In Sanskrit, in any original sequence of two [[sibilants]] the first became a stop (often with further developments): root ''vas-'' {{gloss|dress}}, fut. ''vas-sya-'' > ''vatsya''-; *''wiś-s'' {{gloss|clan}} (nom.sg.) > *''viťś > *viṭṣ > viṭ'' (final clusters are simplified); *''wiś-su'' locative pl. > *''viṭṣu > vikṣu''. English ''amphitheater'' is very commonly pronounced "{{not a typo|ampitheater}}", but this may be explained by [[spelling pronunciation]]. Russian {{lang|ru|конфорка}} {{IPA|[kɐnˈforkə]}} {{gloss|stove burner}} is from Dutch {{lang|nl|komfoor}} {{gloss|brazier}}.

===Lag dissimilation===
Lag dissimilation at a distance (fairly common):
* English ''purple'' is in medieval English as ''purpul'' and ''purpure'' (in medieval French {{lang|frm|porpre}}) and comes from classical Latin {{lang|la|purpura}} {{gloss|purple}} with dissimilation of {{IPA|/r/}} to {{IPA|/L/}}. Latin {{lang|la|rārus}} {{gloss|rare}} > Italian {{lang|it|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 {{lang|la|marmor}}. Russian {{lang|ru|февраль}} {{IPA|/fevrˈalʲ/}} {{gloss|February}} is from Latin {{lang|la|Februārius}}.
* In Spanish, interchanges between {{IPA|/r/}} and {{IPA|/l/}} are common; for a list, see {{slink|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 {{lang|la|hominem}} ("man", acc.) > [[Old Spanish]] {{lang|osp|omne}} > ''omre'' > [[Spanish language|Spanish]] {{lang|es|hombre}}
* Latin {{lang|la|nomine}} ("name", abl.) > ''nomre'' > Spanish {{lang|es|nombre}}
* English ''chimney'' (standard) > ''chim(b)ley'' (dialectal)
* [[Proto-Slavic]] {{lang|sla-x-proto|*svobodà}} {{gloss|freedom}} > [[Slovak language|Slovak]] {{lang|sk|sloboda}} (vs. [[Czech language|Czech]] {{lang|cs|svoboda}})
* In [[Irish language|Irish]], many dialects regularly change the sequence {{IPA|/mn/}} to {{IPA|/mɾ/}}

==Paradigmatic dissimilation==
{{unreferenced section|date=March 2021}}
When, through [[sound change]], elements of a grammatical paradigm conflate in a way not easily remedied by [[periphrasis|rewording]], the forms may dissimilate. For example, in modern [[Korean language|Korean]] the vowels {{IPA|/e/}} and {{IPA|/ɛ/}} are merging for many people in [[Seoul]], and concurrently the second-person pronoun {{lang|ko|네}} {{IPA|/ne/}} {{gloss|your}} is shifting to {{lang|ko|니}} {{IPA|/ni/}} to avoid confusion with the first-person pronoun {{lang|ko|내}} {{IPA|/nɛ/}} {{gloss|my}}.

Similarly, it appears that English ''[[she (pronoun)|she]]'', historically ''heo'', may have acquired its modern ''sh'' form through dissimilation from ''he'', though it is unclear whether the mechanism was idiosyncratic sound change ([[Palatalization (sound change)|palatalization]]) of ''heo'' or substitution for ''heo'' of the feminine [[demonstrative pronoun]] ''seo''.

==See also==
* [[Assimilation (linguistics)]]

==References==
{{reflist}}

==Sources==
* Crowley, Terry. (1997) ''An Introduction to Historical Linguistics.'' 3rd edition. Oxford University Press.
* [https://www.sfu.ca/%7Ealderete/pubs/alderete2003_dissimilationIELArticle.pdf Dissimilation] (''International Encyclopedia of Linguistics'', 2nd ed.)

==Further reading==
* {{cite book |last=Bennett |first=Wm G. <!--sic-->|title=The Phonology of Consonants: Harmony, Dissimilation and Correspondence |publisher=Cambridge University Press |date=2015 |isbn=978-1-139-68358-6 |doi=10.1017/cbo9781139683586 |url=https://www.cambridge.org/core/product/identifier/9781139683586/type/book |url-access=subscription}}

[[Category:Phonology]]
[[Category:Sound changes]]