The five main groups of plural noun formation are as follows. Please note however, that not all nouns are covered in the five groups (the rest will be discussed later in German Plural Nouns II ):
- Plural Nouns With -E Endings
- Plural Nouns With -ER Endings
- Plural Nouns With -N/EN Endings
- Plural Nouns With -S Endings
- Plural Nouns With no End Changes
Most German nouns that consist of one syllable will add -e to form plurals in all grammatical cases. EXCEPTION: in the dative -en is used. Some nouns will also have umlaut changes.
Nouns in this group add –er when plural (-ern in the dative case) and are always either masculine or neuter. There may be some umlaut changes.
These nouns add either –n or –en to form the plural in all four cases. They are mostly feminine and have no umlaut changes.
Similar to English, these nouns add an –s in plural form. They are mostly of foreign origin and have therefore no umlaut changes.
Nouns in this group do not change their word endings in the plural, except for in the dative case where -n is added. There might be some umlaut changes. Most nouns in this group are either neuter or masculine and usually contain one of the following endings: -chen, -lein, -el, -en or -er.

