Assimilation

Assimilation may affect all the features of the articulation of consonant or only some of them.

1. a) the point of articulation, i.e. the principal (alveolar) variants of the phonemes [t, d, n, l, s, z, ] are replaced by their subsidiary dental variants.

b) both the point of articulation and the active organ of speech.

e.g. congress- the forelingual alveolar [n] is replaced by the back - lingual velar [ŋ ] if the prefix con-bears either a primary or a secondary stress.

I can go [ I k∂ n 'g∂ u] → [ I kŋ 'g∂ u] - a vowel between [n] and [k] in an unstressed syllable is omitted in rapid speech so [n] → [ŋ ]

2. the manner of the production of noise

e.g. give me ['gIm mI]

The constrictive noise fricative [v] before the occlusive nasal sonorant [m] at the word boundary in rapid speech is modified. So [v] → [m] - constrictive → occlusive sonorant.

let me ['lem mI] - [t] → [m] - occlusive noise plosive → occlusive sonorant

The manner of noise production is affected by assimilation in cases of:

a) lateral explosion: when a plosive is followed by [l]

e.g. pleasure, candle, cattle

The closure for the plosive is not realized till the off-glide for [l]: the sides of the tongue are lowered and the air escapes along them with lateral explosion.

b) loss of plosion or incomplete plosion in the clusters:

1. of 2 similar plosives [pp, pb, tt, td, kk, kg]

2. of 2 plosives with different points of articulation [kt, dg, tb]

There is only one explosion for the 2 plosives. The closure of the organs of speech for the second plosive is made before the release of the first one.

e.g. a ct, fa ct, goo d g irl

c) nasal plosion - a plosive followed by the syllabic [n, m] has no release, the air escapes through the nasal cavity

e.g. bu tton, su bm arine

3. the work of the vocal cords

A voiceless consonant may be replaced by a voiced one under the influence of the adjacent voiced consonant or vice versa

e.g. goose, goose berry - voiceless [s] → voiced [z]

used, used to - voiced [z] → voiceless [s]

The English sonorants [m, n, l, r, j, w] are partly devoiced when they are preceded by the voiceless consonants [s, p, t, k]

e.g. s m all, p l ease, t r y, s l ow, q u ick, t w enty

4. the lip position

The labialized subsidiary variants of the phonemes [k, g, t, s, ] etc. are used under the influence of the following bilabial sonorant [w]

e.g. quick ['kwIk], twenty ['twentI], language

5. the position of the soft palate

Nasal consonants influence oral ones

e.g. let me [le m mI'] - [t] → [m], oral → nasal

kindness - [d] → [n], oral → nasal