Why do we call a line of poetry a line in English when it is a vers in French (though we do use verse and verses to mean ‘poetry’)? What did Middle English poets call their lines of poetry? In their (at least) trilingual world, they had plenty of words for the basic units of poetry. A metrical line is a versus in Latin (and by extension versus means a set of verses, i.e. a poem). Continental and Insular French usage follows this: a vers is a metrical line. Vers signifies the core unit of poetry, marked out by repeating segments of metre and rhyme. Poetry was in verses whether it was copied as prose (with its units marked by metrical punctuation) or lineated as verse.