The Ninth Principle: On the elucidation of the plural forms of feminine nouns.

a. Know that nouns which appear in the feminine plural are, for the most part, formed with a tav at the end, and the letter before it is pointed with a ḥolam together with a quiescent vav, such as ṣedāqōt, berākhōt, ḥokhmōt, and the like. In the construct state, for example: ṣidqōt Hashem — “the righteous acts of the LORD” (Judges 5:11), birkat avikha — “the blessing of your father” (Genesis 49:26). But in ḥokhmōt śārōtehā — “the wisdom of her princesses” (Judges 5:29), the vowel becomes a pataḥ, because of the presence of a guttural letter.

2. And sometimes the vav is written, and sometimes it is not written. This is called male (plene) or ḥaser (defective) spelling, according to the Mesorah. Likewise, masculine plurals are sometimes found without a yod. For example, ha-tanninim (“the sea creatures”) occurs three times in Scripture with defective spelling; and tsaddiqim (“the righteous”) is written throughout the entire Torah without an additional yod. And there are very many similar cases. [In the Mantua edition: “as I will explain in my work Masoret ha-Masoret, if God wills.”]

3. And there are nouns that are feminine in the singular, marked with a final he, yet form their plural with yod–mem at the end, following the pattern of masculine plurals. Thus, for example: from shanah (“year”) comes shanim; from nemalah (“ant”) comes nemalim; and similar cases. Likewise, some masculine nouns occasionally form their plural according to the feminine pattern, such as av → avot, and bor → borot, and others like them. And there are nouns that occur in both ways, that is, sometimes with a masculine plural and sometimes with a feminine plural, such as: from ḥagor come ḥagurim and ḥagurot; from dor come dorim and dorot. All of this will be explained properly in the chapter on measures.