6. Assimilation.

By assimilation we understand a process of alteration of speech sounds as a result of which one of the sounds becomes fully or partially similar to the adjoining sound. Assimilation can affect the place of obstruction, the active organs of speech, the work of the vocal cords, the position of the lips, the position of the soft palate, the manner of the release of the plosive consonant.

Types of assimilation can be distinguished according to:

1. direction;

2. degree of completeness;

3. degree of stability.

Direction of assimilation.

When some articulatory features of the following sound are changed under the influence of the preceding sound, which remains unchanged, the assimilation is called progressive.

When the following sound influences the articulation of the preceding one the assimilation is called regressive.

When the adjacent sounds influence each other the assimilation is called reciprocal or double.

Consonant influences consonant.

In Modern English it is mainly consonants that are assimilated

The Indication of assimilation	The preceding sound	The following sound	The type of assimilation
1. Modification of the place of obstruction and the active organs of speech.	1. alveolar [t, d, n, l, s, z] 2. alveolar [t, d] 3.bilabial [m] alveolar [n] 4. Interdental [θ, ð]	Interdental [θ, ð] post-alveolar [r] labio-dental [f, v] post-alveolar [r]	Regressive: Alveolar → dental Regressive: Alveolar → post-alv Regressive: Bilabial → lab-dent Alveolar → lab-dent Progressive: Post-alv →alveolar
2. Changes in the work of the vocal cords (voicing and devoicing) Notes: 1. There is no voicing or devoicing of final consonants. 2. Remember! ['ænikdout] ['bə:θdei] ['obstinit] ['medsin] [lets gou] ['æbsənt]	1. voiceless consonants [s, p, t, k, f, θ, ] – voiced consonants and vowels -voiceless consonants -[s, z, , d3] 3.-voiced consonants and vowels -voiceless consonants -[t, d]	Sonorants [m, n, l, r, j, w] suffix -s -[z] -[s] -[iz] suffix -ed -[d] -[t] -[id]	Progressive: Sonorants → partially devoiced Progressive voicing or devoicing Progressive voicing or devoicing
3. Changes in the lip position.	Any consonant	Bilabial [w]	Regressive: consonants become lip-rounded
4. Changes in the manner of the release of plosives.	1. plosives [p, b, t, d, k, g] 2. plosives [p, b, t, d, k, g] plosives [p, b, t, d, k, g] plosives [p, b, t, d, k, g]	Plosives [p, b, t, d, k, g] and affricates fricatives [s, z, θ, ð, f, v] nasal sonorants [m, n] lateral sonorant [l]	Regressive: plosives lose their plosion (the loss of plosion (or incomplete implosion) Regressive: plosives lose their plosion (the fricative plosion) Regressive: plosives lose their plosion (the nasal plosion) Regressive: the plosives lose their plosion (the lateral plosion)

Loss of Plosion. When the plosives meet together within a word the first plosive loses its plosion. The plosion is heard when we pronounce the second plosive.

Nasal Plosion. When the plosives meet with the nasal sonorants the articulation of the sonorants begins when the articulation of the plosives is not finished yet. As a result the air goes through the nose.

Lateral Plosion. When the plosives meet with the lateral sonorant [l] the plosion is heard during the pronunciation of the sonorant as the air passes along the sides of the tongue.

Fricative Plosion. When the plosives are followed by the fricatives there is a loss of aspiration and a release of the first sound during the pronunciation of the second sound.

Difficult consonant clusters.

In the clusters of consonants the place of articulation of which is only slightly different (v-w, f-w, s-θ, z-ð) care should be taken to preserve the quality of each of the adjacent sounds and to avoid the wrong assimilation.

Degree of completeness.

Assimilation is called complete when two adjoining sound become alike or merge into one (cupboard). Assimilation is incomplete, when the likeness of the adjoining sounds is partial as the assimilated sound retains its major articulatory features (sweet).

Degree of stability.

We distinguish obligatory (historical) and non-obligatory (characteristic of fluent or careless speech) assimilation. Non-obligatory assimilation should be avoided by public speakers.

Non-obligatory assimilation.

Accidental or positional assimilations at word boundaries are made by English people in rapid colloquial speech. The alveolar consonants in word final position often assimilate to the place of articulation of the following word initial consonant: before p, b, m the consonant t changes into p, d changes into b, n changes into m. These cases need not be necessarily imitated by foreign learners of English.