The traditional English pronunciation of Latin, and Classical Greek words borrowed through Latin, is the way the Latin language was traditionally pronounced by speakers of English until the early 20th century. Although this pronunciation is no longer taught in Latin classes, it is still broadly used in the fields of biology, law, and medicine.
In the Middle Ages speakers of English, from Middle English onward, pronounced Latin not as the ancient Romans did, but in the way that had developed among speakers of French. This traditional pronunciation then became closely linked to the pronunciation of English, and as the pronunciation of English changed with time, the English pronunciation of Latin changed as well.
Until the beginning of the 19th century all English speakers used this pronunciation, including Roman Catholics for liturgical purposes.Brittain(1955) Following Catholic emancipation in Britain in 1829 and the subsequent Oxford Movement, newly converted Catholics preferred the Italianate pronunciation, which became the norm for the Catholic liturgy. Meanwhile, scholarly proposals were made for a reconstructed Classical pronunciation, close to the pronunciation used in the late Roman Republic and early Empire, and with a more transparent relationship between spelling and pronunciation.
One immediate audible difference between the pronunciations is in the treatment of vowels. The English pronunciation of Latin applied vowel sound changes which had occurred within English itself, where stressed vowels in a word became quite different from their unstressed counterpart. In the other two pronunciations of Latin, vowel sounds were not changed. Among consonants, for example, the treatment of the letter c followed by a front vowel was one clear distinction. That is, the name Cicero is pronounced in English as , in Ecclesiastical Latin as , and in restored Classical Latin as .
The competition between the three pronunciations grew towards the end of the 19th century. By the beginning of the 20th century, however, a consensus for change had developed. The Classical Association, shortly after its foundation in 1903, put forward a detailed proposal for a reconstructed classical pronunciation. This was supported by other professional and learned bodies. Finally in February 1907 their proposal was officially recommended by the Board of Education.Classical Association report on Board of Education Circular 555, February 1907 "The Pronunciation of Latin". The Spectator 6 April 1907, page 10 Adoption of the "new pronunciation" was a long, drawn-out process, but by the mid-20th century, classroom instruction in the traditional English pronunciation had ceased.
Illustrative survivals The traditional pronunciation survives in academic and general English vocabulary: In a very large body of words used every day: album, apex, area, asylum, axis, basis, bonus, camera, census, cinema, circus, crisis, dilemma, error, focus, genesis, genius, hypothesis, icon, insignia, item, junior, major, medium, minor, murmur, onus, panacea, podium, ratio, sector, stamina, terminus, trivia; as well as such common phrases as ad infinitum, et cetera, non sequitur, quid pro quo, status quo, vice versa In academic vocabulary: campus, syllabus, curriculum, diploma, alumnus In anatomical vocabulary: aorta, biceps, cranium, patella, penis, sinus, vertebra, vagina In astronomical nomenclature, including the names of planets, moons, asteroids, stars and constellations: Mars, Io, Ceres, Sirius, Ursa Major, nova, nebula, although non-traditional pronunciations have become established in some cases (traditional for Libra is less common than ) In many biblical names: Ananias, Cornelius, Felix, Jesus, Judas, Lydia, Nicodemus, Nicolas, Priscilla, Sergius, Silas, Titus, Zacharias In a number of historical terms and names, particularly those associated with Greek or Roman culture and politics: augur, bacchanal, consul, fibula, lictor, prætor, toga, Augustus, Cæsar, Cicero, Diocletian, Hypatia, Plato, Socrates, Trajan In legal terminology and phrases: affidavit, alibi, alias, de jure, obiter dictum, sub judice, subpoena. However, some speakers use Classical pronunciation for some of these phrases. In the specialized terminology of literary studies: codex, colophon, epitome, index, periphrasis, parenthesis In some mathematical terms: calculus, parabola, hyperbola, isosceles, rhombus, vector In medical terminology describing diseases, symptoms and treatments: anaesthesia, bacterium, coma, lumbago, mucus, nausea, ophthalmia, rabies, tetanus, virus, rigor mortis In words and names from classical mythology: Achilles, Argus, Calliope, Gorgon, Myrmidon, Sphinx In many place names: Carolina, Judæa, Annapolis, Dalmatia, Ithaca, Nicæa, Pennsylvania, Romania, Salina, Virginia In some religious terms: Angelus, basilica, Magi, martyr, presbyter In many saints' names: Athanasius, Eugenia, Eusebius, Ignatius, Irene, Januarius, Leo, Macarius, Marcella, Theophilus In certain sporting terms: gymnasium, stadium, discus, pentathlon In taxonomic and other biological terminology: phylum, genus, species, chrysanthemum, hibiscus, rhododendron, foetus, larva, ovum, pupa, chameleon, lemur, platypus
Vowel length and stress The English pronunciation of Classical words and names is generally predictable from the orthography, as long as the placement of stress is known as well. However, predicting the place of stress in words of more than two syllables usually requires knowing which vowels in the word were long and which were short in Classical Latin (not to be confused with the so-called "long" and "short" pronunciations of the vowels in traditional English pronunciation itself, which are discussed in detail below). For Latin, Latinized Greek or for long versus short α, ι, υ Greek vowels, this means that macrons must be used if the pronunciation is to be unambiguous. However, the conventions of biological nomenclature forbid the use of these diacritics, and in practice they are not found in astronomical names or in literature. Without this information, it may not be possible to ascertain the placement of stress, and therefore the pronunciation of the vowels in English.
Note that the following rules are generalizations, and that many names have well-established idiosyncratic pronunciations.
Stress placement Latin stress is predictable. It falls on the penultimate syllable when that is "heavy", and on the antepenultimate syllable when the penult is "light".
In Greek, stress is not predictable, but it may be ignored when pronouncing Greek borrowings, as they have been filtered through Latin and have acquired the stress patterns of Latin words.
A syllable is "light" if it ends in a single short vowel. For example, a, ca, sca, scra are all light syllables for the purposes of Latin stress assignment.
Any other syllable is "heavy":
if it is closed (ended) by a consonant: an, can, scan, scran if the vowel is long or a diphthong in Latin, or in the Latin transliteration of Greek: ā, cā, scā, scrā (a long vowel) or æ, cæ, scæ, scræ (a diphthong).
Latin diphthongs may be written or , or . Long vowels are written with a macron: ā ē ī ō ū ȳ, though this is a modern convention. Greek long vowels are ει, η, ου, ω, sometimes ι, υ, and occasionally α. (Long α is uncommon.) For example, Actaeon is pronounced or . A diaeresis indicates that the vowels do not form a diphthong: Arsinoë (not *).
The importance of marking long vowels for Greek words can be illustrated with Ixion, from Greek Ἰξίων. As it is written, the English pronunciation might be expected to be * . However, length marking, Ixīōn, makes it clear that it should be pronounced .
When a consonant ends a word, or when more than a single consonant follows a vowel within a word, the syllable is closed and therefore heavy. (A consonant is not the same thing as a letter. The letters x and z each count as two consonants, but th , ch , and ph count as one, as the pronunciations in brackets indicate.) The English letter j was originally an i, forming a diphthong with the preceding vowel, so it forces the stress just as æ, œ, z, and x do.
Exception: a consonant cluster of p, t, or c/k plus l or r is ambiguous. The preceding syllable was open in ordinary Latin. However, when a different stress placement was required by poetic meter, it could be treated as closed. Thus the name Chariclo (Chariklō) could be syllabified as either cha-ri-klō, with an open penult and stress on the cha (normal Latin), or cha-rik-lō, with a closed penult and stress on the rik (an optional poetic pronunciation), so both and are acceptable pronunciations in English.In the case of Patroclus, which has all short vowels in Greek and Latin and so would normally be , poetic became the established pronunciation in English due to the verse translations of Homer by Alexander Pope, who required penultimate stress to fit his metre.
Secondary stress If more than two syllables precede the stressed syllable, the same rules determine which is stressed. For example, in Cassiopeia (also Cassiopēa), syllabified cas-si-o-pei-a, the penult pei/pē contains a long vowel/diphthong and is therefore stressed. The second syllable preceding the stress, si, is light, so the stress must fall one syllable further back, on cas (which coincidentally happens to be a closed syllable and therefore heavy). Therefore, the standard English pronunciation is . (Note however that this word also has an irregular pronunciation in English: .)
Long and short vowels Whether a vowel letter is pronounced "long" in English () or "short" () is unrelated to the length of the original Latin or Greek vowel. Instead it depends on position and stress. A vowel followed by a consonant at the end of a word is short in English, except that final -es is always long, as in Pales . In the middle of a word, a vowel followed by more than one consonant is short, as in Hermippe , while a vowel with no following consonant is long. However, when a vowel is followed by a single consonant (or by a cluster of p, t, c/k plus l, r) and then another vowel, it gets more complicated. If the syllable is unstressed, it is open, and the vowel is often reduced to schwa. If the penultimate syllable is stressed, it is open and the vowel long, as in Europa . If any other syllable is stressed, it is closed and the vowel is short, as in Ganymede and Anaxagoras .
Regardless of position, stressed u stays long before a single consonant (or a cluster of p, t, c/k plus l, r), as in Jupiter .
Exception: A stressed nonhigh vowel (a, e, o) stays long before a single consonant (or cluster of p, t, c/k plus l, r) followed by an or sound (e, i, y) plus another vowel at the end of a word: Proteus , Demetrius . This is because, historically and regionally, in many of these words the e, i, y is pronounced and combines with the following syllable, so that the preceding syllable is penultimate and therefore open: .