A general rule of English pronunciation states that the 's' in plural nouns is to be pronounced as /z/ if it is preceded by a 'voiced consonant' such as /n/ or /g/, and as /s/ if it is preceded by a 'voiceless consonant' such as /t/ or /p/.
Therefore, "pens" is pronounced as /penz/ and "cats" is pronounced as /cats/.
Now my question is, do native speakers of English always follow this rule? Secondly, and this is what I really need to understand, does this rule apply also to the 's' in the verbs of 'third person singular subjects'?
Best Answer
Yes to both your questions.
Native speakers really do follow that “rule” as to whether being next to a vowel or a voiced consonant makes the -s suffix voiced as well, whereas being next to an unvoiced consonant makes the suffix also unvoiced.
And secondly, the same phonologic law is in operation when constructing a third-person singular verb.
You can also add a third class to that: forming possessives with apostrophe-s.
All three work the same soundwise.