edited by Meagan Ayer et al.

4th Declension: Stem, Paradigm, and Gender

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88. The Stem of nouns of the 4th Declension end in u-. This is usually weakened to i before -bus. Masculine and feminine nouns form the nominative by adding s; Neuters have for nominative the simple stem, but with ū (long).

89. Nouns of the Fourth Declension are declined as follows.

Paradigm for 4th declension nouns

90. Most nouns of the 4th Declension in -us are masculine.


The following are feminine:

acus, anus, colus, domus, īdūs (plural), manus, nurus, porticus, quīnquātrūs (plural), socrus, tribus

with a few names of plants and trees. Also, rarely, penus, specus.

91. The only neuters of the 4th Declension are:

cornū, genū, pecū (see § 105.f), verū1



1. A few other neuters of this declension are mentioned by the ancient grammarians as occurring in certain cases.


The Fourth Declension

The Fourth Declension Neuter

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Suggested Citation

Meagan Ayer, Allen and Greenough’s New Latin Grammar for Schools and Colleges. Carlisle, Pennsylvania: Dickinson College Commentaries, 2014. ISBN: 978-1-947822-04-7. http://dcc.dickinson.edu/grammar/latin/4th-declension-stem-paradigm-and-gender