I don't know of a site like that.
Initial
s is pronounced /s/, except in
sure and
sugar, where it is pronounced /S/*.
Medial
s is problematic. There are no hard-and-fast rules -- mostly just lists.
In -ssion or -ssure, the double S is /S/. impression, pressure
In -sion or -sure, the S is /Z/*. vision, treasure
*/S/ is the sound of "sh" in "sheep". /Z/ is the sound of "s" in "measure" or of "zh" in "Zhivago".
Otherwise “ss” has the sound /s/.
Exceptions where “ss” = /z/ are “Aussie, Missouri, dessert, dissolve,
scissors”, and the first “ss” of “possession”
“sc” before “e”, “i” or “y” acts as if “ss”.
(acquiesce) Otherwise, “sc” is
/sk/. (ascot, Oscar)
Intervocalic “rs”, “ls”, and “ns”. The “s” is /s/. (horse,
else, density, dorsal, conversation, pulse,
pensive)
But when followed by final “y” or “ey” the tendency in this
situation is for “s” to be /z/.
(Mersey, Jersey, pansy, tansy, palsy) Unusual cases with three
intervocalic consonants. parsley (/s/), Guernsey (/z/).
Intervocalic “sp”, “st”*, “sk”. The “s” is /s/. (aspen,
mustard, asking, prosper, hostile, askew)
*But after a stressed vowel, final “stle” and “sten” have a
silent “t”, and “s” is /s/. (castle,
rustle, hasten) Stated differently, in
such contexts “st” has the sound of “ss”.
An exception is “pestle”, which may be pronounced with or without the
/t/.
Intervocalic “sm”, “sn”, “sl”, “sb”, “sd”, “sg”. The “s” is /z/.
(Osmond, osmium, cosmic, Asner, Maslow, Cosby, wisdom, Disney,
frisbie, dismal, paisley) But not in
compounds: (busboy, gaslight)
Final
“-ism” has /z/.
Intervocalic “s” is typically /z/, but it is /s/ often
enough to require memorizing the many exceptions. Note below how the same spellings can be /s/ or /z/, depending on
the word or even the use of the word (noun or verb).
With /s/: case, base, chase, vase,
erase
With
/z/: phase, phrase, laser, quasar
With
/s/: obese
With /z/: these, Chinese, Japanese, and all
"nationality words" in "-ese"
With
/s/: vise, isolate, isobar, and all words with prefix “iso-“.
With /z/: rise, wise, arise, advise, supervise,
improvise, all
prefix + “vise" words, advertise, prison
With
/s/: dose, close (adj), verbose,
morose, purpose, monstrosity, porosity
With /z/: chose, hose, close (v), nose, pose, prose,
rose, those; lose, whose; position
With
/s/ : obtuse, recluse; use, abuse, excuse
(nouns)
With /z/: muse, fuse, ruse, amuse, accuse, profuse,
confuse; use, abuse, excuse (verbs)
With
/z/: raise, praise, braise, raisin, daisy
With /s/: geese, Reese
With /z/: cheese
With /s/: cease, crease, grease*, lease
With /z/: tease, ease, please;
easel, teasel, weasel; reason, season, treason
With /s/: mouse, louse, grouse,
douse (v), house (n)
With /z/: rouse, arouse, carouse;
house (v), lousy; browse, drowse, drowsy
With /s/: moose, goose, loose,
noose, caboose
With /z/: choose
*”grease” has /s/ in the northern
U.S. and /z/ in the southern U.S.
Prefix + root.
With the prefix “trans” it often makes no difference whether
/s/ or /z/ is used.
Speakers vary in their choices.
/s/
or /z/: transpire, transpose, transmit,
transact
Latin prefixes “re”, “de”, “pre” followed by a root
beginning with “s” (and vowel) normally have
/z/.
reserve, deserve, preserve, resort, present, design, resign,
resent, resemble, resolve
But with /s/:
resource, research; reset, resend, all “re-“ meaning “again”.
But Anglo prefixes “be”, “a” followed by a root beginning
with “s” (and vowel) have /s/.
beset, asea, beseech, aside, beside, besiege, asunder
CJ