In poetry , metre ( meter in US spelling ) is the basic rhythmic structure of a verse or lines in verse. Many traditional verse forms prescribe a specific verse metre, or a certain set of metres alternating in a particular order. The study and the actual use of metres and forms of versification are both known as prosody. (Within linguistics , " prosody " is used in a more general sense that includes not only poetic metre but also the rhythmic aspects of prose , whether formal or informal, that vary from language to language, and sometimes between poetic traditions.)
The metre of most poetry of the Western world and elsewhere is based on patterns of syllables of particular types. The familiar type of metre in English-language poetry is called qualitative metre , with stressed syllables coming at regular intervals (e.g. in iambic pentameters , usually every even-numbered syllable). Many Romance languages use a scheme that is somewhat similar but where the position of only one particular stressed syllable (e.g. the last) needs to be fixed. The metre of the old Germanic poetry of languages such as Old Norse and Old English was radically different, but was still based on stress patterns.