While looking up the Igros Moshe on marijuana for another thread, I looked up some Igros on Lashon Hakodesh. very interesting Even Haezer 3, siman 35. The questioner wanted to have gittin differentiate between Jewish names and english names. Reb Moshe ZT”L responds that originally, yiddish names were Goyish German names. there is no difference between goyish German (=yiddish) names and goyish english names. He continues that now the Yiddish names are accepted as Jewish after hundreds of years, but it wasn’t that way originally. so one should protest giving kids English names, but they’re not fundamentally different than Yiddish names. he brings down a peirush mishnayos leRamba”m on Terumos who says what Joseph brought down earlier from another source- Lashon Hakodesh of the Torah is mostly lost to us. The Ramba”m elsewhere does say that Lashon Chachomim (still alive and well) is also a Lashon Hakodesh. Reb Moshe ZT”L continues that despite the mitzvah to speak in Lashon Hakodesh (he quoted a Sifri, forgot to note where), the minhag has always been to speak the “lashon chol” of the golus country, which is why we lost lashon hakodesh. The jews did speak Lashon hakodesh throught bayis rishon. He says names are the same thing. it’s a maaleh to give kids Jewish names, and a maalah to speak lashon hakodesh, but English names are worse than Yiddish names only because they’re not widely accepted.
I tried to find the one about chanoch lenaar al pi darko. Unfortunately, I was not able to. The Yad Moshe can sometimes be confusing. I do not save my Jewish Observers, but it was quoted in one about 5-6 months ago. I will try to hunt it down.