My Spanish teacher, Sra. Castano, speaks using some regional dialect-- one where the C’s that sound like English S’s are turned to ‘th’ sounds. ‘Cinco’ becomes “thinko,” for example. What region is this from, and to what words does it apply?
Thank you. 
This summer, I met a Spanish teacher who mentioned she spent some time in Barcelona. She said that the Bercelonans spoke with a lisp. Apparently, the queen at some time or another had a lisp. All the subjects adopted her lisp and dialect stuck.
I was drinking heavily at the time she told this story, so I may not remember it correctly.
This is “Castillian” Spanish, the “standard” Spanish of Spain. It’s not a regional dialect, but rather the equivalent of the “King’s English” for Spanish.
I can’t post a cite, but my high school Spanish teacher said the accent was based on a Castillian king who had a natural lisp. The aristocracy imitated the way he spoke.
Yet I notice the lisp is not applied to all ‘S’ sounds- that is to say, ‘estoy’ is not ‘ethtoy.’ I know things are not so cut-and-dry in the land of linguistics, but this would cause me to doubt that bit of folklore.
Thanks.
I was in Madrid once and was the first time I’d encountered this. I have heard this royal lisp story and I think it’s a joke. I am not much of a Spanish speaker, but not all sibilant sounds in Castillian are sounded like “th”. Just the “c” and “z”, IIRC. So words like plurals “los angeles” are not lisped. But only IIRC.
I have seen linguists post to the board, hopefully we’ll hear from some.
I heard the same thing about the lisping Spanish royals, but that it was due to congenital birth defects that resulted in severely deformed palates in the family.
That’s a popular story, but it’s basically just a legend.
From here
Latin American Spanish, which doesn’t have the lisp, is primarily descended from Andalusian Spanish, which also lacks it.
As in the footnote, it only applies to c and z, not to s.
PLEASE PLEASE PLEASE stop spreading the “well the king couldn’t pronounce the sound so people started immitating…” line. I’ve heard it used for pretty much every folk etymology of just about EVERY sound imaginable.
It is not a lisp, as much as the “th” in “thing” is a lisp in English. It’s only perceived as a lisp due to the spelling of these words, and our perception of how they should be said.
The “th” sound in Spanish from the Madrid/Northern Castillian area originates from a palatilization of /k/ and /t/ when both were followed by a /j/ (a “y” sound). k and t palatalized into a /ts/ sound, which in Spanish became fully fronted to /T/ (the “th” sound).
Because c could only represent /T/ in front of I or E, Z was used. It had been used for /dz/ came to be used for this same sound (/T/) for a, o, and u (although in Old Spanish, ç was used for this sound). After the 18th century, the Spanish stopped using ç, while French and Portuguese retained it.
The Spanish can very well pronounce the “s” sound. It actually provides more distinction in speech than the Latin American dialects do with words like: casar - to marry and cazar - to hunt (both of which sound the same in Latin American Spanish, but different in Madrileño Spanish)
I don’t follow. In LA Spanish, aren’t they /kasar/ and /kazar/, respectively?
Er, so did Castilian Spanish drop the “cedile” palatal SOUND, or just the letter? Or did they drop the /dz/ sound? Very ambiguous wording here. How is cazar pronounced in modern Castilian Spanish?
Yes, but the two words sound much more similar than the Castilian pronunciations “kasar” and “kathar” do, which I believe was Doobieous’s point.
Short answer to the OP: “What region is this from?”, is simply “Spain” 
As others have noted, not all of Spain, but as a general rule, Spanish speakers from Spain lisp those sounds, whereas those from Latin America do not. I learnt Spanish in the UK and so learnt the “Spanish” pronunciation, so it took some adjustment to deal with the language in Latin America. The same goes for Andalusia - first time I visited Seville, I got some funny looks with my lisping prounciation before it dawned on me that they don’t talk like that there.
In Puerto Rico, for instance, “cazar” and “casar” are both pronouced /ka-SAr/. In Castillian, as Colibrí mentioned, they are pronounced /ka-[ç]Ar/ and /ka-SAr/. (where [ç] stands for the “lithped” sound)
According to the “Real Academia de la Lengua Española” is perfectly standard** for s, z and c-before-i-or-e, to ALL be pronounced with the same “S” sound in Latin American Spanish; and for z and c[i/e] with the “[ç]” sound in Castillian. “z” stands either for S or [ç].
Around here, if we get into a confusion about homophonic words, then we may exaggerate a Castillian accent in order to make it clear what we mean.
(BTW, in standard RALE Spanish, “B” and “V” also are correct to pronounce bith with the same sound, rather than the distinct bilabial plosive/labiodental fricative divide used in English)
Actually, I would say it is Castilian. It is not used in Andalusia, Aragon, the Balearic Islands, Catalonia, Valencia, Galicia, Asturia, etc. Spain is a lot more diverse than most people thing. Heck, Galician sounds more like Portuguese than Castilian.
The bolding is mine. If this wasn’t intentional it has to be the most appropriate typo ever. 
The ‘C’ pronounced as ‘TH’ is not a lisp, as has been noted above. It’s just a peculiarity of the regional dialect.
In Uganda, the Buganda language pronounces ‘K’ as ‘CH’ and vice versa. It’s not “wrong”, just different. It was somewhat disconcerting, however, the first time a worker told me he was going to install a new sink in the ambassador’s “chicken”.
In Spanish translations of the Bible, in the Books of Kings, the king’s name rendered “Ahaziah” in English is given as “Ocozias” in Spanish, with the accent on the i. This reminds me of the “I before E” rule in English…
They are spelled casar and cazar, but they are pronounced the same in Latin American Spanish. They are pronounced differently in Madrileño Spanish.
In Old Spanish “ç” was used for /ts/ (which changed to /T/ “th”). During the spelling reforms of the 18th century the Spanish dropped the use of ç (the
letter ) and used instead c before i and e, and z before a, u, and o for the sound of /T/ “th”.
Cazar is prnounced as /ka’Tar/ something like cah-THAR
Well Galician and Portuguese are almost the same language, except Galician was spared much of the influence by Arabic, while Portuguese was not. They are pretty much mutually intelligible. Galician is also spoken in northern Portugual in Entre Minho e Douro and Tras Os Montes .
After 1495 with the unification of Castille and Aragon, the southern end of the Galician linguistic territory was split and given to the Kingdom of Portugual, where the northern portion was incorporated into the administration of the Junta del Reino de Galicia, which was then incorporated into the domain of Castille and Aragon.