Yeah, hay muchos malvados en la lleil.
Bad hombres. Tá lleno. Y los peores, los de doctorado.
Right. Like that character in Asimov, my last name used to be spelled with a z, but that got changed to an s at some point, so you now spell my name with an s. That wasn’t the name of my ancestors, but if you go back far enough (and probably not very far, all things considered) my ancestors didn’t have surnames at all, so is my current surname wholly incorrect?
It’s impossible to disagree with a source of authority: The authority is correct, by definition, so it always wins. When it comes to personal names, that person is the source of authority, at least once they’re of age.
Speaking of EN-J vs ES-Y, demonstration courtesy of Seth Meyers and America Ferrera. I promise I can hear differences in stress and in the vowels, but I need to take y’all’s word on the first consonant being different.
EN-J, phonetically, has almost every trait in common with ES-Ch (muchacha, champú) except one: ES-Ch is voiceless, EN-J is voiced.
Making that distinction at conversational speed is another matter.
… that makes it sound as if we’d say Cherái for jedi, cháil for jail, chasmín for Yasmin… those two may be officially close but to our ears they certainly are not. We go for ES-Y, which if I’m not mistaken in IPA is phoneme Y, allophones ʝ and ɟʝ, which apparently* are respectively a voiced palatal fricative and a voiced palatal affricative.
Searching for dʒ brings me to pages which try to teach Hispanics how to pronounce dʒ (EN-j) from tʃ (ES-ch), but given that it’s not the similarity we see, I’m not sure it’s a good method. It may explain why some people do say ES-ch for EN-j when speaking English: they were taught to do it that way.
- It’s been almost 40 years, plus I learned phonetics in Spanish and the names aren’t exactly parallel, which is business as usual but doesn’t facilitate bilingual work damnit
Also, I haven’t found a page that had the same level of detail for English and Spanish.
Another little detail: at some level, each person’s perception is coloured by the language(s) they know best. My silly example: ES-b and ES-v sound the same… OK, good… When someone speaks English with a strong Spanish accent, obviously they will by accident pronounce EN-b and EN-v the same too… OK… But my English-only ears don’t hear b and v sounding the same - instead, I consistently hear “Vovvy and Bictor were playing bolleyvall” - as if all the B’s and V’s were exchanged, instead of just equalized. I hear what’s “wrong” with the sound, instead of hearing the sound as it really is. I expect this happens often, that we hear each other’s “mistakes” much more clearly than we hear each other’s actual sounds.
I really hope that made some sense. 
Makes perfect sense to me. You have someone whose command of your language is perfect except for some little bit, and the little bit somehow becomes as large as a ship’s ram. Even if you really don’t mind, you notice that little detail every single time. And it may be something correctable (such as confusing two similar words) or it may not (what do you mean, those two words don’t sound the same? You’ve said them three times and I can’t hear what’s different!).
When Mexicans are confronted with the English name “John,” they usually assume their closest equivalent for the initial consonant is “y,” which is too soft – that is, not enough friction between tongue and palate, even if it DOES have more friction than an English “y” sound. Actually, the Spanish (and English) “ch” sound works equally well – as others have noted, it has the same friction (closure) as English “j,” just without voicing.
(Mexicans would also do better thinking of the “o” in “John” as like the Spanish “a,” but that’s a story for another thread.)
When my surname-line ancestors came to America, they split into two groups: My line kept the German spelling, but pronounces it like an English-speaker would, while the slightly-better-known branch kept the German pronunciation, but spells it like an English-speaker would. I sometimes therefore get called by the German pronunciation, especially by people who have some exposure to German, and while I consider it a mistake, I don’t consider it a major one.