In the process of speech, that is in the process of transition from the articulatory work of one sound to the articulatory work of the neighbouring one, sounds are modified. These modifications can be conditioned:
a) by the complementary distribution of the phonemes, e. g.
the fully back /u:/ becomes back-advanced under the influence of
the preceding mediolingual sonorant /j/ in the words tune, nude.
The mid-open, front /e/ becomes more open followed by the dark 1 in hell, tell, sell. Compare with bet, let, set.
In the word keen /k/ is not so back as its principal variant, it is advanced under the influence of the fully front I'v.l which follows it.
b) by the contextual variations in which phonemes may occur at
the junction of words, e. g. the alveolar phoneme /n/ in the combina
tion in the is assimilated to the dental variant under the influence of
/3/ which follows it.
c) by the style of speech: official or rapid colloquial. E. g.
slight pressure /'slait ipreja/ may turn into /islaipipreja/ in collo
quial speech, similarly hot muffins /ihut ImAfmz/ may turn into