Inflection of Substantives.

Five cases are reconstructed for Proto-Germanic, with traces of a sixth; these are: nominative, vocative, genitive, dative, accusative, and instrumental. The nominative is the case used to indicate the subject, and never follows a preposition. The vocative is the case of address. The genitive indicates relationships among substantives, often possession. In addition to being governed by specific prepositions, the dative indicates the indirect object; the accusative, the direct object. The instrumentalcase has a distinct form in only one paradigm; it indicates a relationship involving means, similar to that of adverbs. Two further cases are reconstructed for Proto-Indo-European: the locative, which according to some specialists has left reflexes in certain Germanic paradigms, and the ablative, to which certain Germanic adverbs have been related.

There are three genders: masculine, feminine, and neuter. These categories are primarily grammatical, although there is also relationship to sex. That distinction is found largely with nouns referring to animate beings, as in Go. niþjis 'male relative', niþjō 'female relative'; frijōnds 'friend', frijōndi 'woman friend'; ON Freyr 'the god Frey', Freyja 'the goddess'. Gender distinction is also found in the third person pronouns.

Substantives are inflected for three numbers: singular, plural, and dual. The dual is strongly represented only in pronouns and in PGmc was losing ground there. Like gender, number is also primarily a grammatical category, not always a category with literal meaning, as the following examples from Old Saxon indicate:

With the exception of gender, the categories of inflection were less distinct in Proto-Germanic than in Proto-Indo-European and were reduced further in the dialects, where some of them were ultimately lost, such as gender in English with covert usage persisting primarily in the use of personal pronoun 'he, she, it'. Similarly, except in the personal pronouns only two cases remain in English, the genitive and the unmarked case. Further, the category of number is overt only in the noun, in a few verb forms likeam, is in contrast with are, and in the indication of person in the third singular present, e.g. writes as opposed to write in the plural and other categories.

Inflection is indicated through the suffixes known as endings. As noted above, in Proto-Indo-European and early Proto-Germanic the endings were suffixed directly to roots. But affixes were added to roots already in Proto-Indo-European to form bases, also known as stems, and the endings were attached to these. When the stress accent was introduced, it generally fell on the root; weakly stressed syllables then were often reduced, so that the endings in Proto-Germanic and its dialects consisted of merged suffixes and the early endings. Classes of inflections in late Proto-Germanic were labeled by these. Three declensions then resulted:

1. Root nouns (which are poorly attested);
2. Consonant stems;
3. Vocalic stems in two sets: the o/ā stems, and the vocalic resonant stems.

Reconstructed forms illustrating each of the noun classes are given in paradigms below. Reflexes in the dialects are included, to provide evidence for the Proto-Germanic forms that have been reconstructed. In the paradigms of the dialects attested forms are preferred. But our limited texts do not provide us with complete inflections for most nouns; accordingly some unattested forms are included without being starred, such as the Gothic nominative dags.