Słownik angielskiego

Plural forms of the surnames follow the pattern of the masculine and feminine forms respectively, if such exist.

Plural forms of the names quite rarely follow the patterns of regular declension, even if the name is identical with a common name.

Plural forms are, like in many Slavic languages, somewhat complex.

Plural forms of verbs without a verbal plural marker are translated as duals.

Plural forms do not differ in deictic meaning.

Plural forms meaning "only, alone" also occur.

Plural forms differ from word to word depending on the word's gender, root, and historical stress.

Plural forms can be a bit more complicated (see below).

Plural forms that are distinguishable from the singular outside of liaison environments occur only with adjectives ending in -al.

See the Wikipedia entry on Plural form of words ending in -us for a full exposition .