Assimilation (phonology)

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Assimilation" phonology – news · newspapers · books · scholar · JSTOR (September 2009) (Learn how and when to remove this message)

In phonology, assimilation is a sound change in which some phonemes (typically consonants or vowels) change to become more similar to other nearby sounds. This process is common across languages and can happen within a word or between words. For example, in English "handbag" (/ˈhændbæɡ/), the [n] often shifts to [m] in rapid speech, becoming /ˈhæmbæɡ/, because [m] and [b] are both bilabial (produced with both lips), and their places of articulation are similar.

It occurs in normal speech but is more frequent in faster speech. Sometimes the change is accepted as canonical, and can even become recognized in standard spelling: implosion pronounced with [m], composed of in- + -plosion (as in explosion).

Sound segments typically assimilate to a following sound,^{[note 1]} but they may also assimilate to a preceding one.^{[note 2]} Assimilation most commonly occurs between immediately adjacent sounds but may occur between sounds separated by others.^{[note 3]} For example, in "handbag," the [d] is sometimes elided (omitted), which causes the [n] to assimilate to [m] before the [b].

Assimilation can be synchronic, an active process in a language at a given point in time, or diachronic, a historical sound change—for instance, "cupboard," historically a compound of "cup" (/kʌp/) and "board" (/bɔːrd/), is now pronounced /ˈkʌbərd/, with the original /ˈkʌpbɔːrd/ almost never used.^{[note 4]}

A related process, coarticulation, includes changes like vowels nasalizing (taking on a nasal sound) before nasal consonants (/n, m, ŋ/) due to premature soft palate (velum) lowering, or /b/ labializing (lips rounding) as in "boot" ([bʷuːt̚]) or "ball" [bʷɔːɫ] in some accents. This article describes both processes under the term assimilation.

Cite error: There are <ref group=note> tags on this page, but the references will not show without a {{reflist|group=note}} template (see the help page).