A double plural is a
plural form to which an extra
suffix
In linguistics, a suffix is an affix which is placed after the stem of a word. Common examples are case endings, which indicate the grammatical case of nouns, adjectives, and verb endings, which form the conjugation of verbs. Suffixes can carry ...
has been added, mainly because the original plural suffix (or other variation) had become
unproductive and therefore irregular. So the form as a whole was no longer seen as a plural, an instance of
morphological leveling.
Examples of this can be seen in the history of
English and
Dutch. Historically, the general English plural markers were not only ''-s'' or ''-en'' but also (in certain specific declensions) ''-ra''/''-ru'' (which is still rather general today in
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
under the form ''-er''). The ancient plural of ''child'' was "cildra/cildru", to which an ''-en'' suffix was later added when the ''-ra''/''-ru'' became unproductive; the Dutch plural form ''kind-er-en'' and the corresponding
Zeelandic form ''kind-er-s'' are also double plurals which were formed in the same way as the English double plurals, while for example German and
Limburgian have (historically conservative) single plurals such as ''Kind-er''.
''Breeches'' is an example involving an old plural that did not use a suffix. It was formerly ''breech'' which came from Old English ''brec'' which was the plural of ''broc''.
References
{{ling-morph-stub
Grammatical number
Historical linguistics
Linguistics