In English, the pronunciation of the final “s” sound in words depends on the voicing of the preceding sound:
/s/: After voiceless consonants (e.g., /p/, /t/, /k/, /f/, /θ/), the “s” is pronounced as /s/. Examples include “hats” (/hæts/), “cups” (/kʌps/), and “laughs” (/læfs/).
/z/: After voiced consonants (e.g., /b/, /d/, /g/, /l/, /m/, /n/, /v/, /ð/, /r/, /ŋ/) and vowel sounds, the “s” is pronounced as /z/. Examples include “dogs” (/dɒgz/), “pens” (/pɛnz/), and “flies” (/flaɪz/).
/ɪz/: After sibilant sounds (e.g., /s/, /z/, /ʃ/, /ʒ/, /tʃ/, /dʒ/), an extra syllable is added, and the “s” is pronounced as /ɪz/. Examples include “buses” (/ˈbʌsɪz/), “wishes” (/ˈwɪʃɪz/), and “judges” (/ˈdʒʌdʒɪz/).
These rules apply to plural nouns, possessives, and third-person singular verbs.
