How are English spellings determined for words from languages with logographic writing systems. Since these don't have an alphabetic script the words in the original language don't have a "spelling." So when originally writing these words in English you cannot simply transliterate character for character such as can be done with, for example, Greek.
Since the original script is usually describing a phonetic syllable (AFAIK) it would make sense when writing it in English to use the appropriate letter or combination of letters for each phoneme. When it is a sound not used in English one would use the closest approximation.
What I'm wondering is how so many far eastern language loanwords and names ended up with such odd English spellings.
Chinese place names beginning with "x" in English. These words are pronounced with an "s" or "sh" sound. How did we end up using an "x" to represent them?
How did feng shui get it's spelling? Most English speakers pronounce it ''fung shway." The e makes sense since the actual pronunciation is more like a "ə" but the "i" at the end makes no sense.
This phenomenon is especially prominent in Korean words and place names. Daehhak-ro is pronounced more like "Tay-on-lo." Cheong-ryang-ri is more like "Tung-yon-lee " These are of course approximated but the spellings seem way off. Even the capital seems oddly spelled. As far as I've ever heard native speakers pronounce it exactly the same as we pronounce the word "soul." Why the extra "e?"
An exception seems to be Japanese. Nearly all Japanese words seem to be spelled just as one would expect. Perhaps Japanese phonemes are closer to English than the other far eastern languages?
If there was a spelling that was retained from the original language, such as for European or Arabic words, it makes sense. Then have to go back to the original language to find out why it has a non-standard spelling. But when the language doesn't have a "spelling" in the phonetic sense of the word why don't we just spell them as they sound?