Broken plural

In linguistics, a broken plural (or internal plural) is an irregular plural form of a noun or adjective found in the Semitic languages and other Afroasiatic languages such as Berber. Broken plurals are formed by changing the pattern of consonants and vowels inside the singular form. They contrast with sound plurals (or external plurals), which are formed by adding a suffix. It is distinct from Germanic umlaut, a form of vowel mutation found in Germanic languages.

There have been a variety of theoretical approaches to understanding these processes and varied attempts to produce systems or rules that can systematize these plural forms.

While the phenomenon is known from several Semitic languages, nowhere has it become as productive as in Arabic.

In Arabic, the regular way of making a plural for a masculine noun is adding the suffix -ūn[a] (for the nominative) or -īn[a] (for the accusative and genitive) at the end. For feminine nouns, the regular way is to add the suffix -āt. However, not all plurals follow these simple rules. One class of nouns in both spoken and written Arabic produce plurals by changing the pattern of vowels inside the word, sometimes also with the addition of a prefix or suffix. This system is not fully regular, and it is used mainly for masculine non-human nouns; human nouns are pluralized regularly or irregularly.

Broken plurals are known as jam‘ taksīr (جَمْعُ تَكْسِيرٍ, literally "plural of breaking") in Arabic grammar. These plurals constitute one of the most unusual aspects of the language, given the very strong and highly detailed grammar and derivation rules that govern the written language. Broken plurals can also be found in languages that have borrowed words from Arabic, for instance Persian, Pashto, Turkish, Kurdish, Azerbaijani and Urdu. Sometimes in these languages the same noun has both a broken plural Arabic form and a local plural. E.g. in Pashto the word for "purpose" (مطلب) matlab can be pluralised in either its Arabic form مطالب matālib for more formal, High Pashto, or the plural مطلبونه matlabūna in everyday speech. (Cf. the treatment of Latin words in English; e.g. the plural of index is either indices or indexes, the latter being more informal.)

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