Assimilation (phonology)

Assimilation is a regular and frequent sound change process by which a phoneme changes to match an adjacent phoneme in a word. If the phoneme changes to match the preceding phoneme, it is progressive assimilation. If the phoneme changes to match the following phoneme, it is regressive assimilation. If there is a mutual influence between the two phonemes, it is reciprocal assimilation. In the latter case the two phonemes can fuse completely and give a birth to a different one. This is called a coalescence.

Assimilation may result in the neighbouring segments becoming identical, yielding a geminate consonant; this is complete assimilation. In other cases, only some features of phonemes assimilate, e.g. voicedness or place of articulation; this is partial assimilation.

Examples

Complete assimilation:

The word assimilation itself (from Latin ad + simile)
illegible (in + legible)
suppose (sub + pose)
in Italian: Egitto (tt < pt), dottore (tt < kt), and many more

Partial assimilation:

voicing: the pronunciation of absurd as apsurd
voicing: bats (bat + the plural morpheme s, which is underlyingly /z/)
place of articulation: impossible (in + possible), incomplete (in which n represents the velar nasal)

Numerous examples can be found at List of Latin words with English derivatives.

See also