19.14 Most nouns of the first declension are feminine. Some nouns of the first declension, however, are MASCULINE, particularly those referring to a specifically male person. In such instances, three changes occur:
The NOMINATIVE SINGULAR adds –ς.
The GENITIVE SINGULAR uses the masculine –ου ending.
Otherwise, masculine nouns follow the basic rules for all other first declension nouns. Observe the following (cf. S 222):
(cf. G 71)
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