Editing Consonant mutation (section)

=== English ===
{{See also|Consonant voicing and devoicing#English}}
In Old English, velar stops were [[Palatalization (sound change)|palatalized]] in certain cases but not others. That resulted in some alternations, many of which have been [[morphological leveling|levelled]], but traces occur in some word doublets such as ''di'''tch''''' {{IPA|/dɪ'''tʃ'''/}} and ''di'''k'''e'' {{IPA|/daɪ'''k'''/}}.

In the past tense of certain verbs, English also retains traces of several ancient sound developments such as *kt > *xt and *ŋx > *x; many of them have been further complicated by the loss of {{IPA|/x/}} in Middle English.
* ''see'''k''''' {{IPA|/siː'''k'''/}} : ''sou'''gh'''t'' {{IPA|/sɔːt/}}
* ''thi'''nk''''' {{IPA|/θɪ'''ŋk'''/}} : ''thou'''gh'''t'' {{IPA|/θɔːt/}}

The pair ''tea'''ch''''' {{IPA|/tiː'''t͡ʃ'''/}} : ''tau'''gh'''t'' {{IPA|/tɔːt/}} has a combination of both this and palatalization.

A second palatalization, called [[yod-coalescence]], occurs in loanwords from [[Latin]]. One subtype affects the [[sibilant consonant]]s: earlier {{IPA|/sj/}} and {{IPA|/zj/}} were palatalized, leading to an alternation between alveolar {{IPA|/s z/}} and postalveolar {{IPA|/ʃ ʒ/}}.
* ''confe'''ss''''' {{IPA|/kənˈfɛ'''s'''/}} : ''confe'''ssi'''on'' {{IPA|/kənˈfɛ'''ʃ'''ən/}}
* ''fu'''s'''e'' {{IPA|/fjuː'''z'''/}} : ''fu'''si'''on'' {{IPA|/ˈfjuː'''ʒ'''ən/}}

Another unproductive layer results from the Vulgar Latin palatalization of velar stops before front vowels. It is thus imported from the Romance languages, and {{IPA|/k ɡ/}} alternate with {{IPA|/s dʒ/}}.
* ''indu'''c'''e'' {{IPA|/ɪnˈdjuː'''s'''/}} : ''indu'''c'''tion'' {{IPA|/inˈdʌ'''k'''ʃən/}}
* ''ma'''g'''ic'' {{IPA|/ˈmæ'''dʒ'''ɪk/}} : ''ma'''g'''us'' {{IPA|/meɪ'''ɡ'''əs/}}

A combination of inherited and loaned alternation also occurs: an alternation pattern *t : *sj was brought over in Latinate loanwords, which in English was then turned into an alternation between {{IPA|/t/}} and {{IPA|/ʃ/}}.
* ''ac'''t''''' {{IPA|/æk'''t'''/}} : ''ac'''ti'''on'' {{IPA|/ˈæk'''ʃ'''ən/}}