In Thai language, there are 3 /s/ sounds in high class consonant. Students might wonder how to use them and why we have 3 different symbols just to represent only one sound.
Actually, we follow the origin of words in writing system although we might not pronounce them as the native speakers do. In Sanskrit language, there are ศ ษ and ส because they pronounce them differently.
If you know how to read and write Thai, you will notice that Pali language and Sanskrit language influence Thai language deeply. In Pali and Thai, there are only ส while the 3 consonants are used in Sanskrit. That means all words with ศ or ษ are originally from Sanskrit.
During 1940 – 1944, the government of Field Marshal Plaek Phibunsongkhram specified to use only ส; however, ศ and ษ resumed again after that. Nowadays we write ศ ษ or ส following the writing rules of Pali-Sanskrit.
If you don’t have any clues about Pali-Sanskrit, I’d like to suggest you to remember words by heart. If not, feel free to learn both before coming back to learn Thai. LOL Have fun!!!
Some example words of ศ
ประกาศ (n/v) announce; announcement
พฤศจิกายน (n) November
พิศ (v) look, watch
เลิศ (adj/adv) excellent
ศรัทธา (v) believe in
ศัตรู (n) enemy
ศาล (n) court; shrine
ศาสนา (n) religion
Some example words of ษ
กษัตริย์ (n) king
พฤษภาคม (n) May
พิษ (n) poison
ภาษา (n) language
ภาษี (n) tax
รักษา (v) medical treat, cure
Some example words of ส
ทาส (n) slave
พฤหัสบดี (n) Thursday
วาสนา (n) fortune, destiny
สงฆ์ (n) monk
สวรรค์ (n) heaven
สัตย์ (n/adj) honest
สัตว์ (n) animal
สาร (n) text, message
สูตร (n) formula
หงส์ (n) swan
โอกาส (n) opportunity