User:Ghoti/A simple and unreliable rule for pronouncing "s" based on its adjacent sounds

In this page the sounds /s/ and /z/ of the letter "s" are explored. It can be seen than in many cases the sound is voiced (/z/) if the adjacent sounds also are. A simple rule is as follows:
 * Initial "s" is always /s/ (the only exceptions are "sugar" and "sure")
 * Final "s" is pronounced according to the pronunciation of the morpheme “-s”, with many exceptions
 * If "s" is between vowels it is often pronounced /z/
 * If "s" is adjacent to at least one consonant it is often pronounced /s/

The "rules" shown here doesn't always hold. A better approach is in Advanced decoding exercises: /s/ vs /z/.

Many words that are spelled with "s" are pronounced with /s/ while others are pronounced with /z/. Students who have never heard the words must memorize them. Heteronyms are particularly relevant here.

This article doesn't explain other sounds, such as /ʃ/ or /ʒ/. The digraph "ss" is not studied here.

Color code
Green: the rule holds, no exceptions

Yellow: the rule holds, there are exceptions

Red: the rule doesn't hold

Blue: the rule doesn't hold, however, there are no exceptions

Initial
No words beginning with /z/ are spelled with "s". When there are mute or redundant consonants we may ignore them.

Final
(*) See Pronunciation of the morpheme “-s”

adj. adjective, n. noun, v. verb n., etc any part of speech except verb


 * homophones /s/: peace/piece
 * homophones /z/: freeze/frees (v.); maze/maize/Mae's; pause/paws; please/pleas; raise/rays; size/sighs


 * minimal pairs: advice - advise; bus - buzz; face - phase; hiss - his; ice - eyes; grace - graze; lice - lies; loose - lose; niece - knees; once - ones; peace - peas; place - plays; price - prize; race - raise/rays; rice - rise;
 * heteronyms: abuse (n. - v.); close (adj. - v.); excuse (n. - v.); house (n. - v.)


 * silent "s": Arkansas - debris - Illinois

Mid-position
n., etc any part of speech except verb v. verb


 * minimal pairs: precedent/president
 * heteronyms: resent /rɪˈzent, riːˈsent/

Adjacent to consonants
Note: In this section and the next a silent "r" (as in "course") is considered a consonant.

Initial
There is only one possibility: sound /s/ spelled "s"

Final

 * minimal pairs: dense - dens; since - sins; tense - tens;


 * silent "s": corps

Vowel is first

 * silent "s": aisle - island

Summary
Looking at the red-and-yellow rows above, the following pairs of words summarize the /s/-/z/ exceptions to the adjacency "rule". Note that here there are more exceptions than if we thought the "rule" does not apply. See Advanced decoding exercises: /s/ vs /z/.
 * atlas - herpes (nouns)
 * yes - as (other)


 * goose - cheese (nouns)
 * increase - cause (verbs)


 * basic - music (nouns)
 * disembark - desire (verbs)


 * dense - cleanse
 * hospital - husband
 * parsley - Thursday
 * answer - damsel

Variant pronunciations
Some words may be pronounced either with /s/ or with /z/. In some cases there is a regional variant.


 * absorb - explosive - resource - treatise - usage
 * /s/ in BrE, /z/ in AmE: asthma /ˈæsmə, ˈæzmə/
 * /z/ in BrE, /s/ in AmE: blouse - diagnose - erase

Several personal names spelled with "s" are pronounced with either /s/ or /z/.


 * Denise - Jesus (normal pronunciation is /ˈdʒiːzəs/; altenative pronunciation is /ˈdʒiːzəz/) - Joseph - Josephine - Lisa - Teresa - Theresa