Assimilation (phonology)

Assimilation is a phonological process by which one sound becomes more similar to a nearby sound. This change is motivated by ease of articulation, as speakers tend to modify sounds to be more easily produced in a particular phonetic environment. Assimilation can be either anticipatory (regressive) or perseverative (progressive).

• Regressive Assimilation (Anticipatory Assimilation): In regressive assimilation, a sound is influenced by a sound that follows it. In other words, a sound changes to become more like the sound that comes after it. The direction of influence is from right to left.

• Progressive Assimilation (Perseverative Assimilation): In progressive assimilation, a sound is influenced by a sound that precedes it. A sound changes to become more like the sound that came before it. The direction of influence is from left to right.

Assimilation can affect various phonetic features, such as:

• Place of Articulation: For example, /n/ in "in possible" may be realized as /m/ due to the following /p/ sound, both being bilabial consonants.
• Manner of Articulation: For example, a stop consonant may become a fricative due to the influence of a nearby fricative.
• Voicing: A voiceless consonant may become voiced due to the influence of a nearby voiced sound, or vice-versa.
• Nasalization: A vowel may become nasalized due to the influence of a nearby nasal consonant.

Assimilation can be complete or partial. In complete assimilation, the affected sound becomes identical to the influencing sound. In partial assimilation, the affected sound only adopts some of the features of the influencing sound.

Assimilation is a common process in many languages and contributes significantly to the phonetic variation observed in speech. It is an important concept in understanding phonological rules and processes.