Latin Vowels and Diphthongs

Last week, I posted something about the incompleteness of the written record - both in Latin and in English - for the reproduction of speech. Although alphabetic writing is pretty good at recording word items consistently, in the flow of speech, words change in context, and there are often sound alterations that take place based on that context. When words and endings come into contact, and when one word and another word come into contact, there is a tendency for assimilation to take place at those contact boundaries. One common form of assimilation is voicing, that is, when a devoiced consonant becomes voiced (the "s" at the end of the English word "drags"). Another type of assimilation is devoicing, when a voiced consonant becomes voiceless (like the "d" at the word boundary in the English phrase "used to"). Because we have plenty of examples of English speakers to listen to, we can see how the English written record does not perfectly reflect English pronounciation. In Latin, we are in a bind - there are some clues about the kinds of assimilation that were found in Latin speech, but the clues are few and indirect. In the absence of direct oral evidence, any attempts to reproduce Latin speech are a guess on our part - which is why I am an enthusiast about speaking Latin, but not especially interested in the competing claims for what constitutes "authentic" ancient pronunciation.

The unhelpful alphabet. In this post, I thought I would say a bit more about phonetics, since that is something usually not very well addressed in beginning language textbooks, especially Latin. Again, it is the tyranny of the written language which tends to get in the way of our doing a good job with phonetics. The way we usually introduce students to the sounds of Latin is by working our way through the alphabet from start to finish. Perhaps we separate out the vowels, but that is usually the only concession made to phonetic structure. It is the order of the alphabet which dominates, and the order of the alphabet bears no relationship to the underlying phonetic structure of the Latin language. (Note for a later post: the Semitic origins of the Latin alphabet.)

If you look at the pronunciation guide in the front of your Latin textbook or dictionary, I would bet money that it is organized by alphabet. All the information is there - but it is very hard to process because it is basically chaotic. A non-phonetic organizing principle - the alphabet - is being used to organize something that really does have structure. It's as if you were to organize the food in your pantry shelves based on the price of the item, or the books on your bookshelves based on the colors of the cover - the items are "organized" but the nature of the organization is such that the result is actually chaos. Organizing Latin phonetic material by the order of the Roman alphabet is just as chaotic.

Vowels. Luckily, this one concession is usually made to linguistic structure: the vowels are treated separately from the consonants. Despite the dearth of linguistic instruction in our schools today, people do still learn the difference between vowels and consonants, although they usually memorize the list of vowels without learning just what it is that makes a vowel a vowel. What does the word itself mean? The origin of the word "vowel" gives a clue: it is ultimately derived from the Latin adjective vocalis, meaning "voiced," something pronounced with the vox, a "voice" or "sound." A vowel is something that sounds, a sound that you can make. Try it: you can make what we call an "a sound," an "e sound," an "i sound, etc., and sustain that sound for as long as your breath holds out. Just try it: like when the doctor tells you to say "aaaaaaaa," you can say "aaaaa" for as long as you have breath. When you are cooing with delight at something, you can say "ooooo" or "uuuuuuu" for as long as your breath lasts. (You cannot make consonant sound by itself; that is why they are called "con-sonants," something that has to be pronounced with a vowel; I'll have more to say about that in a later post.)

More technically, a vowel is a sustained sound you can make by letting breath move through your vocal apparatus (throat, mouth, lips and also nose). The quality of the individual vowel depends on the vertical position of the tongue in your mouth: vowels like [i] and [u] are made with the tongue up high, while a vowel like [a] is made with the tongue lowered. You can also think of it in terms of how open your jaw is; for a high vowel your jaw is more closed, and for a low vowel your jaw is more open. The mid-vowels, such as [e] and [o], which are in-between the range of high/closed and low/open vowels.

The position of the tongue towards the back or front of your mouth is also a factor in vowel production, with the vowels [e] and [i] being towards the front and [o] and [u] towards the back, and [a] more centrally. Other factors involved in vowel quality are the roundedness of your lips and whether or not any air is let out through your nose ("nasalized" vowels).

"Feel" the triangle. Taking the most basic vowel features into account - high (closed) versus low (open), and front versus back - you end up with a kind of triangle of vowels in your mouth. The [a] sound is low (open), and more or less central, not really front or back. As you move up from [a] towards the high front [i] you get one side of the triangle, passing through [e]. As you move up from [a] towards the high back [u], you get the other side of the triangle, passing through [o]. Moving from the high back [u] to the high front [i] gives you the third side of the triangle. For a nice diagram, see the Wikipedia article about vowels.

You can actually "feel" this in your mouth. It's easy to slide from one vowel into another without breaking the flow of air. It's just a matter of moving the tongue and jaw. Just try making a sustained [a] sound and then shift into making the [i] sound. Can you feel how the vowel moves "up" and your jaw "closes" at the same time, with the sound transitioning through [e] on the way up to [i]? It should feel like you are moving up from [a] through [e] through [i]. Now trying moving up from [a] to the [u] sound. Can you feel how the vowel is moving up and your jaw closing, while you pass though the [o] sound on your way up to [u]? There are basically two trajectories, moving up from [a] to [i] through [e] and moving up from [a] to [u] through [o].

Now try the reverse, going from [i] down to [a]. See how different that feels from going up from [a] to [i]? For most people, their jaw tends to drop quickly, without much of a glide. It's easy to get a glide going up [a-i], but harder to sustain the glide as your jaw drops going down [i-a]. Now try the back version, going from [u] down to [a]. See how different that feels from going up from [a] to [u]? Again, it's easy to get a glide going up [a-i], but harder to sustain the glide as your jaw drops going down [i-a].

That then leads us naturally to the phenomenon of diphthongs (ai, au, etc.) and to the phenomenon of semivowels (i becoming y/j, and u becoming v/w). In more technical terms, the sounds I am calling diphthongs here - ai, au, etc. - are classed more specifically as "closing" diphthongs. This is because the high vowels [i] and [u] are also considered "closed" vowels, based on the way your jaw tends to close as you pronounce them. I'll have more to say about closing versus opening diphthongs in my next post.

Latin diphthongs. Meanwhile, I hope I can persuade you today that it is useful thinking about the natural way diphthongs are formed in the mouth, as opposed to the arbitrary way they are listed in most Latin pronunciation guides. Usually, diphthongs are presented as an alphabetical list of letter combinations without any attention to how and why diphthongs result from the natural physiology of voice production. Now that you understand the [a] to [i] trajectory in the front of your mouth, and the [a] to [u] trajectory in the back of your mouth, I hope you will find it easier to see the Latin diphthongs as a system, and to have a good understanding of just why some diphthongs are more common than others.

First, there is the trajectory from low [a] up to the high front [i]. There is where you will find the Latin vowel sound represented by the spelling "ae" in Latin. In classical Latin, this sound is though to have tended more to a high front direction [a-i], rhyming with English "by," despite the spelling "ae" (it might have been better spelled as "ai"). As an aside, you can also use this knowledge of physiology to get a clue here about the tendency that led us English-speakers to pronounce "Caesar" as we do: we have taken the Latin diphthong "ae" (really more like [a-i]) and pushed it to the absolute extreme, so that the [a] component is completely gone, and we end up with just the [i]. Caesar.

Along that same [a] to [i] trajectory, there is another Latin diphthong, represented by the spelling "ei" and pronounced like the sound in English "they." This diphthong, however, is not very common at all in Latin. Along the [a] to [i] trajectory, the "ae" is the dominant diphthong in Latin.

Now think about the glide trajectory from [a] up to [u]. This is where you will find the Latin diphthong represented by "au" and pronounced like the vowel sound in English "now." This is a very common sound in Latin. Together, the sounds "ae" and "au" represent the most commonly found diphthongs in Latin.

In addition to these glides moving up from [a] towards the high front [i] and the high back [u], there are also glides that cross from back to front and vice versa, although these are less common. The glide from [e] to high back [u] is spelling "eu" and is notoriously difficult for English speakers to pronounce, since it is not commonly found in English. It is also not that common in Latin, and is usually found in borrowings from Greek.

The glide from [o] to high front [i] is written "oe" in Latin, and it is pronounced to rhyme with English "boy." Just as the Latin "ae" was probably pronounced in a range between [a-e] and [a-i], the sound represented by "oe" was probably pronounced in a range between [o-e] and [o-i], and could just as easily have been spelling "oi." If you have studied Greek, you will know from that Greek does not use the spelling "ae" and "oe" for its diphthongs, but spells them instead as αι and οι, with the letter "i" instead of the letter "e" as the second element.

So, I'll leave it at that for now, and next week I'll turn to the literally "jaw-dropping" phenomenon of semivowels or, as they are sometimes called, opening diphthongs. Meanwhile, I hope you have enjoyed this romp through the vowel sounds back to front and low to high. The way we use our mouth and tongues to create these sounds is quite amazing. We can do so without thinking exactly about what we are doing, but when you go to study a foreign language, I believe it helps to use this formal knowledge to compensate for the lack of "natural" language acquisition opportunities - the kind that babies do so well!

Finally, I thought I would close with an interesting item here from the Wikipedia article. In addition to the standard charts showing vowel articulation, I was fascinated to see these X-ray images by the linguist Daniel Jones, who was a pioneer in the field of the scientific study of pronunciation in the early 20th century (According to some, Jones is the man who provided George Bernard Shaw with the model for Henry Higgins in My Fair Lady.) In addition to "feeling" what is happening with your tongue and jaw, you can actually take a look at it here in the pictures; click on the image for a larger view: