The Spanish and some other Latin root languages have simplified ph words that come from the Greek; philosophy becomes filosophie, elephant is elefante, etc.
Psaltery becomes Saltario, etc.
In many German words, the h in th is silent, e. g., thaler is pronounced taler.

Non-English speakers are stuck with learning native English usages of these words from friends and teachers- there are some rather variable rules, but they are not taught in ESL (English as a Second Language) courses. The origins of these words and their evolution are given in the complete Oxford English Dictionary, but most of us learn them by ear.

Thorn, them, thee, come from Old English, old German, Norse, etc.; many non-English will silence the h, thus torn, tem (dem), tee-

As the King said. "'Tis a puzzlement" ("The King and I").

Proper names of people and places are 'a whole nother ball game'.