When I was in school my Latin teacher told me that “Caesar” as in Julius Caesar was pronounced “Ki-zer”. My question is how do we know they (the classical Romans) pronounced it that way? (As opposed to Sez-ar-ay or c-zar)
You don’t make your email available so I had to post here, not to reply to your question but just to say that you have a great signature. I used to watch that show all the time and I thought I was the only one who did. Much later I found out that there is even now a devoted following.
Whose side are you on?
That would be telling.
Be seeing you.
Dont forget that Julius was pronounced Yu-lee-us. Have to defer to a linguist on why.
Basically, the way we know how anything was pronounced is to examine places where they are used:
- there are a few (not many) commentaries among the writers of the time;
- we can look at words that are rhymed;
- we can look at manuscripts where words that sound alike are written with the “wrong” word inserted (one method of “publication” was to have a reader dictate to a room full of scribes who transcribed what they heard. If we did this, today, and found a passage “he through the door open,” we would have a good idea that through rhymed with threw.);
- we can see how the word is transcribed into other languages (e.g., the family name Caesar became the title of the ruler of Rome and shows up in Greek texts as Kaisar).
In vulgar latin, it was probably pronounced as /kesar/ (like kay-sar). In fact, the diphthong “ae” often became “e” (like spanish e) in the Romance languages, hence: Cesár*.
- In western Romance languages like Spanish and Portuguese, /k/ before i or e became palatalized, going from /k/ to /ts/ to /T/ (“th”) in modern Castilian Spanish, and finally to /s/ in most Latin American Spanish (the evolution’s probably a tad more involved, but this is what I gathered from my book on the subject).
While i diverge onto this tangent, i’ll mention what happened to a few of the other diphthongs, using Spanish as an example:
au > o: aurum > oro
ae > e: caesar > Cesár
oe > e: poena > pena
It also appears in later Romance that ai turned to e, as in the ending -ariu: -ariu > airo > ero: e.g. panadero
There is much more, and this is all from what i’ve read (“From Latin to Romance in sound charts”, and “Vulgar Latin” by Jozsef Herman)
Since the Romans didn’t have tape recorders, the best we can do is educated guesses. That said, the guesses we have are pretty educated. People have been studying LINGVA LATINA for nearly as long as it has existed.
There are a variety of hypotheses linguists use to reconstruct pronunciations of dead languages. The first and most important is the spellings that the writers of the languages themselves used. Any language that uses a phonetic alphabet at least starts out spelling its words phonetically; often the spellings will become fossilised while the oral language continues to evolve, and for that we have no better example than Modern English, which was written down about 100 years too early 
So if the Romans wrote down his name as
CAIVS IVLIVS CAESAR,
which they did, we can suspect (at the very least) that, for instance, the first two sounds in the first and third words are going to be roughly the same (“CA”). If the Romans had pronounced his cognomen the way Americans do today, they’d have spelled it “SISVR”. You can expect, then, that the Romans pronounced the word to resemble something like “Kie-sar” or “Kie-zar”; we certainly have precious little idea what their accent would sound like, but the basic shape of the word is pretty well known.
Other clues linguists use are: The way things are pronounced in languages descended from the dead tongue, along with a large number of well-established rules about how phonetic use changes with time (for instance, a “k” sound will often change into a “ch” sound, but the other direction never occurs; stuff like that); if there are other languages being written at the same time (in this case, Greek is particularly good, because it was the language of the educated Roman), some things are often transliterated, names especially. This is, for instance, how we know almost for certain that classical Latin used a “w” sound when they wrote the letter “V” as a consonant. The name VARIVS, for instance, is transliterated into classic Greek as (roughly) “oo-arioose”; if the first letter had had a “v” sound, the transliteration would have been something like “farioose” instead. (And how do we know how the Greeks sounded? Well, again, we use educated guessing.)
What I have always wondered is how it is known that the Latin “V” had a “W” sound…for instance Caesar’s famous “Veni, Vidi, Vinci” boast was supposedly more like “Weni, Widi, Winchi”. However no modern romance language has a V with a W sound…well you have the “w” vowel sound in a Spanish word like huésped French oui , and Italian * uomo *. However in Spanish it V became a hybrid B/V sound and in French, Portuguese, and Italian, a V.
The shift from “C” before i or e going from a K to a s (French, Latin AMerican Spanish), th (Castilian), z or s (Portuguese) and ch (Italian, …and Romanian?) makes more sense because they are divergent sounds.
But anyway…I ain’t no linguist or nothing…
First, it’s “VENI VIDI VICI”, they’re all four letters. Second, it sounds more like “way-nee, wee-dee, wee-kee”. As far as linguists can tell, there was no “ch” sound in classical Latin.
Again, two pieces of evidence (for the “w” pronunciation). First, the way the Romans used the letter. There is no doubt that they used it as their vowel “U”; there simply was no letter U in the Romans’ alphabet. They were also “missing” some other letters like J, K and W (they used K sometimes in Greek loan words, but that was it; J and W just plain hadn’t been invented yet). So when they wrote “Julius”, they wrote it IVLIVS and pronounced it (more-or-less) “yoo-lee-oos”. However, V did double-duty as a consonant as well. There is no argument that when the Romans used a “QV” in a word, for instance QVID PRO QVO, it sounded like an English (or Italian or Spanish) “qu”.
Now if they pronounced the word “VENI” so that it started with a “v” sound, you’d think they’d come up with a new letter, or use something that sounds a little closer to “v” than a “u” or a “w”. This fact alone argues that Romans pronounced the word “way-nee”. But that’s not the only evidence we have. We also have classic Greek, and I went over an exact example in my previous post, so please go back and read it.
“w” --> “v” and “k” --> “ch” are very common sound migrations in languages, and it’s not surprising (to a linguist, anyway) that these changes have occurred in some or all of the Romance languages.