A heavy syllable is a syllable with a branching nucleus or a branching rime, although not all such syllables are heavy in every language. A branching nucleus generally means the syllable has a long vowel or a diphthong; this type of syllable is abbreviated as CVV. A syllable with a branching rime is a closed syllable, that is, one with a coda ; this type of syllable is abbreviated CVC. In some languages, both CVV and CVC syllables are heavy, while a syllable with a short vowel as the nucleus and no coda is a light syllable. In other languages, only CVV syllables are heavy, while CVC and CV syllables are light. In yet other languages, CVV syllables are heavy and CV syllables are light, while some CVC syllables are heavy and other CVC syllables are light. Some languages distinguish a third type, CVVC syllables and/or CVCC syllables as superheavy syllables. In moraic theory, heavy syllables are analyzed as containing two morae, light syllables one, and superheavy syllables three. The distinction between heavy and light syllables plays an important role in the phonology of some languages, especially with regard to the assignment of stress. For instance, in the Sezer stress pattern in Turkish observed in place names, the main stress occurs as an iamb one syllable to the left of the final syllable: σ. However, when the foot contains a heavy syllable in the first syllable while the second syllable is light, the iamb shifts to a trochee because there is a requirement that main stress fall on a heavy syllable whenever possible: σ, and not *σ.
Classical poetry
Basic definitions
In Ancient Greekhexameter poetry and Latin literature, lines followed certain metrical patterns, such as based on arrangements of heavy and light syllables. A heavy syllable was referred to as a longum and a light as a brevis. A syllable was considered heavy if it contained a long vowel or a diphthong or if it contained a short vowel that was followed by more than one consonant. An example: The first syllable of the first word is heavy because it contains a short vowel followed by more than one consonant — and if not for the consonants coming after it, it would be light. The second syllable is light because it contains a short vowel followed immediately by only one consonant. The next syllable is light for the same reason. The next syllable, the second syllable of the wordvirumque, is heavy because it contains a short vowel followed by more than one consonant. But, for example, the first syllable of the word Troiae is heavy because it contains a diphthong, regardless of the sounds coming after it. Likewise, the first syllable of the second line is heavy because it contains a long vowel, and it will be heavy no matter what sounds come after. Terming a syllable "long by position" is equivalent to noting that the syllable ends with a consonant, because Latin and Greek speakers in the classical era pronounced a consonant as part of a preceding syllable only when it was followed by other consonants, due to the rules of Greek and Latin syllabification. In a consonant cluster, one consonant ends the preceding syllable and the rest start the following syllable. For example, Latin syllabifies volat as vo-lat but dignus as dig-nus and monstrum as mon-strum.
Exceptions and additions
A few exceptions to and elaborations of the above rules of heavy and light syllables:
The Greek letters ζ, ξ, ψ and their Roman equivalents Z and X were pronounced as two consonants, so they lengthen by position despite being represented by a single character. For example, the first syllable of gaza is heavy, despite the short vowel followed only by one written consonant, because the Z was pronounced as two consonants and lengthens the syllable by position.
The combination stop–liquid or stop–nasal cohered in both Latin and Greek; that is, the two consonants were pronounced together with the speed of one consonant. As a result, they did not lengthen by position if the poet did not want them to. For example, the first syllable of patris is generally light, even though it has a short vowel followed by two consonants, because the consonants cohere. However, the combination aspirate-nasal or voiced consonant-nasal did not cohere and always lengthened by position.
In Homer and his imitators, the digamma, a sound defunct in the standard Ionic alphabet and lost from pronunciation by the classical period, was still felt enough to lengthen by position, even though it is normally not written in the Homeric poems. For example, in the line ἦ τοι μὲν τόδε καλὸν ἀκουέμεν ἐστὶν ἀοιδοῦ, the first syllable of καλὸν is long, even though it has a short vowel followed by only one consonant, because the word was originally καλϝὸν, and the digamma was still felt enough to lengthen the syllable by position. Since the digamma was being lost during the time when the Homeric poems were composed, recited, and written down, its effects are sometimes not felt, so that words that would have contained a digamma sometimes do not show its effects.
As noted above, the number and order of heavy and light syllables in a line of poetry articulated the meter of the line, such as the most famous classical meter, the epic dactylic hexameter.
