In linguistics, a broken plural (or internal plural ) is an irregular plural form of a noun or adjective found in Semitic languages and other Afrasian languages such as Berber . Broken plurals are formed by changing the structure of consonants and vowels within a singular form. They contrast with sound plurals (or external plurals), which are formed by adding a suffix, but also formally differ from phenomena such as German umlaut , a form of vowel mutation used in the plural in Germanic languages .
There are various theoretical approaches to understanding these processes and various attempts to create systems or rules that can systematize these plural forms. However, the question of the origin of broken plurals for languages that show them is not resolved, although there are certain probabilities in the distributions of specific plural forms with respect to specific singular patterns. As transformations go far the degree of mutations caused by the German umlaut, which is apparently caused by inflectional suffixes , the variety of forms corresponds to multiplex attempts of historical explanation, from sentences of transfonologization and multiple accent changes to switching between categories of groups, abstracts and plural or nouns.