How can I know when to pronounce the s as a z sound when speaking English?

Question

The /z/ sound in English happens after a vowel, another /s/ or a voiced consonant the /s/ is pronounced as a /z/.

Examples: logs, tubes, beds, moves, clothes, was, becomes, he’s, passes.

Also when /s/ is followed by ‘es’ pronounce it as /epsilon+z/, after / s, z, ch, sh, j, dz/.

Examples: passes, beaches, washes, packages, noses.

However, like many pronunciation skills to master...the easiest way is to have a speech language pathologist specializing in accent modification help you memorize them!

Answer 1

Although English has few general rules, and there will be exceptions to these guidelines, this outline will be helpful:

the /z/ sound comes after a vowel, another /s/, or what is called a voiced consonant--easiest way to think about it is a hard sound.

e.g. was or he's (vowel pronounced); moves or beds (hard or voiced consonant)

the /s/ sound comes after a after an unvoiced or soft consonant

e.g. laughs, moths, tops

the 'es' after some plural words is pronounced as a schwa sound, like a very short 'u'

To tell when a consonant is voiced vs unvoiced, put your hand on your throat when you say it, and if it vibrates, it will likely be a voiced consonant.

Voiced consonants tend to be:

b, d, g, j, l, m, n, ng, r, sz, th,* v, w, y, z

Unvoiced:

ch, f, gh, k, p, s, sh, t, th*

*as you can see there is some irregularity, and some of it comes down to memorization