prosody, the study of versification; in Greek and Latin in particular, the study of the rules which govern the quantity (i.e. length) of syllables in verse (see METRE, GREEK 1). Syllables are classified according to the length of time they took to pronounce and are called long, short, or anceps (‘ambivalent’, i.e. either long or short). A syllable is long or short ‘by nature’ according as it contains either a long vowel or diphthong, or a short vowel. The general rules of Greek and Latin prosody (to which there are exceptions) are the following.
1. Greek
(i) By nature the vowels η and ω are long, ɛ and ο short; ɑ, ι, and υ are sometimes long by nature, sometimes short. Diphthongs are long (i.e. ɑι, ɑυ, ει, ευ, ηυ, οι, ου, υι, ᾳ, ῃ, ῳ), except that οι and ɑι, which appear to have been of shorter duration, are sometimes scanned short.
(ii) A syllable long by nature is sometimes shortened if it comes immediately before another vowel. This happens most often at the end of a word (i.e. before another word beginning with a vowel). The shortening is known as correption (and see (iii) below).
(iii) A syllable that is short by nature is lengthened in pronunciation, and so becomes long ‘by position’, if the vowel is immediately followed by two (or more) consonants or by a so-called double consonant, ζ (= sd), ξ (= ks), or ψ (= ps), whether or not the consonants are in the same word. There is an exception to this general rule: in Attic poetry (which includes tragedy and comedy), a naturally short syllable usually remains short if it is followed by one of several combinations of two consonants, the first a so-called ‘mute’ (for this purpose one of π, β, ϕ, τ, δ, θ, ϰ, γ, χ), and the second a ‘liquid’ (λ, ϱ, μ, ν). This phenomenon is known as Attic correption.
2. Latin
(i) The vowels a, e, i, o, u (and y) are sometimes long by nature, sometimes short. Diphthongs (ae, au, ei, ou, oe) are long. A vowel which immediately precedes another vowel in the same word but is not part of a diphthong is generally short.
(ii) Correption of a final long syllable (see 1 (ii) above) is rare.
(iii) A syllable that is short by nature is lengthened in pronunciation, and so becomes long ‘by position’, if the vowel is immediately followed by two (or more) consonants, or by a double consonant, x (= ks) or z (= Greek ζ). (When the ‘semi-consonants’ i and u are equivalent to English j or v they are counted as consonants; h is discounted; qu is counted as a single consonant.)
(iv) An exception to (iii) is that short syllables remain short before certain combinations of so-called ‘mute’ and ‘liquid’ consonants (compare 1 (iii) above), i.e. b, c, d, f, g, p, t followed by l or r. This licence does not occur when the two consonants belong to different words or to different parts of a compound verb (e.g. ābrumpere).