· the sound in the flection is assimilated under the influence of a vowel or voiced consonant, thus becomes [z]
· the sound in the flection is assimilated under the influence of an unvoiced consonant, thus becomes [s]
3.When two sounds come together as a result of the juxtaposition of two words, there is one single, elongated articulation of the consonant, so called prolongated pronunciation(the native speakers do not pronounce the consonant twice). In case the second word in a phrase is stressed, the second sound is pronounced with a little prominence, thus, it is louder:
[s] - let’s stay [`letsstei]
[ʃ] - English ship [`ingliʃʃip]
[g] - big garden [big`ga:dn]
[k] – black cup [blæk`kʌp]
Notice! When [tʃ], [dʒ] come together, both sounds are pronounced.