3. Assimilation affecting the lip-position results in labialized allophones of consonants before such phonemes as /w, u:, O:/: twenty, twice, tall, quick, tool.
4. Assimilation affecting the manner of producing noise results in:
a) plosionless allophones of /p b, t d, k g/ (loss of plosion); when they follow one another either within a word or at the junction of words the first plosive loses its plosion: actor /k t/, Big Ben /g b/, donít talk /t t/, put down /t d/, eight pounds /t p/.
b) When /p b, t d, k g/ are followed by the fricatives or affricates their plosion becomes fricative (fricative, or incomplete plosion): past five /t f/, temperate zone /t z/, hot summer /t s/.
c) When /p b, t d, k g/ are followed by the nasal sonorants /m, n/ their plosion becomes nasal: garden /d n/.
d) When /p b, t d, k g/ are followed by the lateral sonorant /l/ their plosion becomes lateral: middle /d l/, circle /k l/, good luck /d l/, uncle /k l/, little /t l/.
Note. When /p, t, k/ are preceded by /s/ they lose their aspiration: skate /s k/, steak /s t/, space /s p/.
Word stress (word accent) is greater prominence given to one or more syllables in a word.
Stressed and unstressed syllables differ in quantity (length) and quality. They are longer when stressed and carry vowels of full formation. When unstressed, they undergo reduction and become shorter.
Word stress should be considered from the point of view of:
1) its place in a sentence;
2) its degree.
There are two degrees of word stress in English:
1) primary or strong (marked above the syllable);
2) secondary or weak (marked under the syllable).
The place of word stress depends on the quantity of syllables in a word.