How & When to Pronounce /ʃ/
/ʃ/ is a voiceless fricative sound made slightly further back in the mouth than /s/, the sides of the tongue are touching the teeth, and the lips can be a tiny bit rounded. It is most commonly the SH in FISH and SHOE, the CH in CHEF and MACHINE, and the S in SURE and PASSION. It’s also found in word endings like the TI in EMOTION, the CI in SOCIAL and the CE in OCEAN, altogether now – /ʃ/
Shush!
Shhhh is the universally recognised English exclamation requesting quiet and is also found in verb form – SHUSH. Originally it came from the verb HUSH, which is also a noun, so a bit of HUSH then please. Of course, there are other options here, SHUT UP, SHUT IT, SHUT YOUR TRAP, or evenSHUT YOUR CAKE HOLE are impolite, and contain the /ʃ/ sound. You can request quiet whilst sounding boorish without pronouncing /ʃ/ with the idiom PUT A SOCK IN IT!
Latin Derivation
Some imported French words are spelt CH and pronounced /ʃ/ like CHEF, CHAMOIS, MACHINE,CHIC and MOUSTACHE, but others are with affricate /tʃ/, like CHANGE and ARCH. So in the popular name girl’s name CHARLOTTE we find /ʃ/ but in its male equivalent CHARLES, it’s /tʃ/ . We’ve also taken MACHETE from Spanish and PISTACHIO from Italian. DELICIOUS!
Sexual Issues (& Schedules)
If you are posh, you may have “sexual issues” without /ʃ/, whereas common folk have sexual issues with /ʃ/. A similar pattern appears in TISSUE, NEGOTIATE and several words ending -CIATE, something we all APPRECIATE. In British English, we tend to say /ʃ/ in SCHEDULE, whereas in American it’s with /sk/, so SCHEDULE.