IPA phoneme /z/

In English, both in Received Pronunciation and in General American, the IPA phonetic symbol /z/ corresponds to the initial consonant sound in words like "zoo", and "zebra" and the final one in "sneeze" and "jazz". It is normally spelled with "s" as in "does" or "cousin".

/z/ is a voiced consonant; its unvoiced counterpart is IPA phoneme /s/. Care must be taken to the fact that in many examples the letter "s" represents /s/ and in many others it represents /z/.

Words with "z"

 * with inital /z/: zapping - zebra - zero - zone - zoo
 * with final /z/: amaze - booze - buzz - breeze - freeze - gaze - prize - size
 * in "mid"-position: citizen - crazy - dizzy - dozen - cozy - lazy - magazine

Words with "s"

 * with final /z/: always - as - because - cause - cheese - choose - close (v.) - clothes - cruise - his - lose - news - pause - please - positive - propose - result - raise - rise - series - sometimes - surprise - these - those - use (v.) - whose - wise
 * Plural: answers - dogs - dreams - eyes - flies - friends - gardens - hospitals - jobs - keys - leaders - lives - shoes - things - watches
 * Third person singular: approaches - buys - considers - does - drags - fills - finds - flies - has - is - loves - maintains - seems - sings - tries - was


 * See also Pronunciation of the morpheme “-s”


 * between vowels: acquisition - busy - cosy - cousin - design - desire - disease - easy - museum - music - opposite - pleasant - position - positive - presence - present (n. and v.) - president - prison - proposal - reason - reserve - resident - resist - resolve - result - season - visit - user


 * other: business - husband - observe - Thursday - Tuesday - Wednesday

Words with "ss"
Normally "ss" sounds /s/. The following exceptions sound /z/. This list is fairly complete (obvious derivatives are not included).
 * Aussie - brassiere - dessert - dissolve - hussar (a soldier) - Missouri - possess - possession - scissors

Words with "x"

 * X as /gz/: exactly, examine, example, executive, exist

Verbs ending in /aɪz/
Verbs ending with the suffix "ise" can be spelled with "s" or "z" in British spelling and only with "z" in American spelling.


 * emphasise - emphasize; organise - organize; realise - realize; recognise - recognize;

Verbs ending with the suffix "yse" are spelled with "s" in British spelling and with "z" in American spelling.
 * analyse - analyze; dialyse - dialyze;

If /aɪz/ is not part of a suffix, then only one spelling is used
 * size - surprise

Homophones

 * clause - claws; freeze - frees (third person); size - sighs (plural and third person); pause - paws; raise - rays; ways (plural) - weighs (third person);


 * What is the difference between a cat and a comma?
 * A cat has its claws at the end of its paws and a comma has its pause at the end of its clause.

Greek plurals
Words of Greek origin ending in -sis /sɪs/ make their plurals ending in -ses /siːz/.
 * analysis /əˈnæləsɪs/ - analyses /əˈnæləsiːz/; crisis /kraɪsɪs/ - crises /kraɪsiːz/;

These words don't rhyme
/z - s/
 * demise - concise; please - lease;
 * compromise /ˈkɒmprəmaɪz/ - promise /ˈprɒmɪs/

Heteronyms

 * present: (n. and adj.) /ˈprzənt/, (v.) /prɪˈznt/
 * use: (n.) /juːs/, (v.) /juːz/
 * used to: modal verb /juːst tə/, normal verb followed by "to" /juːzd tə/

Clippings
Some words that are spelled with "s" are shortened with "z"
 * business - biz; show business - showbiz; president - prez;

Respellings

 * Waze is an application used to find your ways.

Spanish L1
In Spanish either [z] does not exist, or (in some dialects) it is the sound of "s" before some consonants: mismo pronounced [mizmo]. In any case /z/ is perceived identical to /s/ by Spanish speakers. Most of them need to be convinced of the difference between words like hiss and his, or price and prize. This is a frequent issue, because /z/ appears in many everyday words like third person singular of verbs plays, does, goes, was, has, is, he's, she's, not to mention many plurals, such as eyes, trees, dogs, etc. See Pronunciation of the morpheme “-s”.

Note that in the following grammar words "s" is pronounced /s/: this - thus - us - yes

This is explained in Pronunciation and decoding exercises: /s/ vs /z/, and with a lot of detail in Advanced decoding exercises: /s/ vs /z/.