Syllable rime

In the study of phonology in linguistics, the rime or rhyme of a syllable consists of a nucleus and an optional coda. It is the part of the syllable used in poetic rhyme, and the part that is lengthened or stressed when a person elongates or stresses a word in speech.

The rime is usually the portion of a syllable from the first vowel to the end. For example, /æt/ is the rime of all of the words at, sat, and flat. However, the nucleus does not necessarily need to be a vowel in some languages. For instance, the rime of the second syllables of the words bottle and fiddle is just /l/, a liquid consonant.

"Rime" and "rhyme" are variants of the same word, but the rarer form "rime" is sometimes used to mean specifically "syllable rime" to differentiate it from the concept of poetic rhyme. This distinction is not made by some linguists and does not appear in most dictionaries.

Rhyme structure

The simplest model of syllable structure divides each syllable into an optional onset, an obligatory nucleus, and an optional coda. The illustration to the right demonstrates this model with the English words cat and sing.

There exist, however, many arguments for a hierarchical relationship, rather than a linear one, between the syllable constituents. This hierarchical model groups the syllable nucleus and coda into an intermediate level, the rime, as shown in the illustration to the left. The hierarchical model accounts for the role that the nucleus+coda constituent plays in verse (i.e., rhyming words such as cat and bat are formed by matching both the nucleus and coda, or the entire rhyme), and for the distinction between heavy and light syllables, which plays a role in phonological processes such as, for example, sound change in Old English scipu and wordu.

Just as the rime branches into the nucleus and coda, the nucleus and coda may each branch into multiple phonemes. The two illustrations below demonstrate English words with branching nucleus and coda, respectively.

Syllable final

In the phonology of some East Asian languages, especially Chinese, the structure of a syllable is expanded to include an additional, optional segment known as a medial, which is located between the onset and the rime. The medial is normally a glide consonant, but reconstructions of Old Chinese generally include liquid medials (/r/ in modern reconstructions, /l/ in older versions), and many reconstructions of Middle Chinese include a medial contrast between /i/ and /j/, where the /i/ functions phonologically as a glide rather than as part of the nucleus. In addition, many reconstructions of both Old and Middle Chinese include complex medials such as /rj/, /ji/, /jw/ and /jwi/. The medial groups phonologically with the rime rather than the onset, and the combination of medial and rime is collectively known as the final.

Some linguists, especially when discussing the modern Chinese varieties, use the terms "final" and "rime/rhyme" interchangeably. In historical Chinese phonology, however, the distinction between "final" (including the medial) and "rime" (not including the medial) is important in understanding the rime dictionaries and rime tables that form the primary sources for Middle Chinese, and as a result most authors distinguish the two according to the above definition.