The stress in compound and polysyllabic words

a) the place of articulation

Thus, alveolar phonemes [t], [d], [n], [l], [s], [z] are replaced by their dental variants if they are followed by interdental sounds [D], [T]. Sounds [t], [d] are replaced by their post-alveolar variants when followed by [r]:

at the, width, on the, all this; trace, dread.

b) both the place of articulation and the active organ of speech

In the words with the stressed prefix – con- when it is followed by the consonants [k], [g] the forelingual alveolar sound [n] is replaced by the backlingual velar[N]:

congress, concrete.

c) the manner of the production of noise

1) When two plosive consonants are in contact within a word or at a word junction there’s a complete loss of plosion of the first sound:

midday, blackboard, actor, accept, bookcase, football, weekday, what kind, good girl, hot bottle, talked.

2) At the junction of the plosive consonants with the nasal sonorants [m], [n] we observe nasal plosion:

student, sudden, didn’t, wouldn’t, modern, department, admit, appointment, right now, shipmate.

3) At the junction of the plosive consonants with lateral sonorant [l] we observe the lateral plosion:

kettle, apple, black, bottle, clock, plan, middle, I don’t like.

4. 
   When a plosive consonant precedes a fricative consonant [s] we observe fricative plosion:
   

sets, wants, legs, besides, rugs, takes, lamps, upside, outside, needs, I think so.

d) the work of the vocal cords.

This assimilation takes place at the junction of a voiceless consonant and sonorants [w], [l], [ r], [ j]. The sonorants are partially devoiced when preceded by a voiceless consonant:

pray, try, throw, cream, sweater, sweep, twilight, climb, fly, stupid, tune, pure, few.

c) the lip position

If consonants [k], [g], [t], [s], [d] precede sonorant [w], they become labialized, or lip-rounded:

twist, twice, sweater, swim, question, quite, dwelling, bad weather, language, Gwendolyn, persuade.

As far as the direction is concerned, assimilation may be progressive, regressive and double (reciprocal).

Progressive assimilation can be represented by the formula A→B where the assimilated consonant is influenced by the preceding sound: free, price.

In regressive assimilation the preceding sound is affected by the following one: A←B – in them, maple.

In double assimilation two adjacent sounds influence each other: A↔B – twenty, tree.

According to the degree of completeness assimilation may be complete,