The term ḥarf (pl. ḥurūf, aḥruf) ‘part, particle, edge, end, boundary’ is used in Arabic linguistic terminology to indicate (1) the final segment formed as a result of the linear segmentation of the Arabic word; (2) a component of the prosodic, morphological, and lexical pattern of a word; (3) any discrete unit of an Arabic text that has a linguistic function (word, morpheme); (5) a certain class of linguistic units; or (6) one of the parts of speech, against nouns and verbs.

As a polyvalent notion, the term ḥarf has no equivalent in the conceptual system of European linguistics (F…