How to spell ʃ (and brief note on English spelling)

     English spelling is notoriously problematic. It's a mashup of several different spelling conventions, made worse by a number of inconsistencies. Teaching spelling is also problematic. English-speaking countries focus on letters instead of sounds, so much so, that some English speakers refer to "alphabetic languages". Another result of this focus is the insistence on correct spelling for words that are never confused when speaking. That's just two (too, to) effects of confusing letters and sounds.

     Every language uses a specific set of sounds, called phonemes. Most languages use around three dozen phonemes. An "accent" consists of variations of the phonemes, and may have more or fewer phonemes than the standard version. The English alphabet is borrowed from the ancient Romans, with a few additions. We have 26 letters for about 40 sounds. Q and X each spell two sounds, which could be spelled KW and KS. C duplicates the sounds of S and K. In effect we have only 23 letters. So we use letter combinations (which include  "silent letters"), and spelling conventions that signal different sound values. But for many common words, one must memorise the spelling.

     And there's a twist: English speakers are more willing to adopt foreign words than just about anybody else. Along with the words we usually adopt the foreign spellings. So we end up with multiple spellings for the same sound.

     One of these sounds is the one that begins "she". It has more spellings than any other sound. Here are the most familiar ones:

How to spell ʃ

Common words:
oCEan
groCery *
CHef
caCHE
suspiCIon
Sugar
nauSEous
faSCist
conSCIence
SHine
aSSure
seSSIon
naTIon

From other languages:
FuCHSia
GauTHier **
SCHnapps

* Regional dialect
** Pronunciation varies

Footnote 1: Linguists have identified about 400 distinct sounds used by the known languages. Another linguistics concept is the "morpheme": think of it as a unit of meaning. For example combine the base "dog" (which refers to an animal) with "s" (which means "more than one), and you get "dogs".  Some linguists refer to the spelling unit as a "grapheme": a letter or combination of letters that spells a single phoneme, or some conventional combination of phonemes.

Footnote 2: Phonemes and sounds are not the same. The essence of a phoneme is that it signals a difference in meaning. Thus in "sing" and "sang", the sounds spelled by "a" and "i"  are phonemes  because  the two words have different meanings. On the other hand, the  sounds spelled by "ng" in "singer" and "finger" are different in most English dialects, but the difference is ignored. If they were phonemes, then "singer" rhymed with "finger" would be a different word than its usual pronunciation. (And in "ginger", "ng" spells a combination of three phonemes.)

Footnote 3: Homonyms come in two varieties: two words with the same spelling but different sounds (and meanings), called homographs. And two (or more) words with the same sound but different spellings (and meanings), called homophones. The study of homonyms helps one to understand the difference between a sound and a phoneme.

Footnote 4: Almost every phoneme in English is spelled two or more ways. Every letter and most letter combinations stand for two or more phonemes.