Irregular plurals

Words ending in -L:

if stress is on the last syllable: al → ais, il → is, ul → uis, el → éis, al → óis

• e.g. normal → normais

if stress is on the penultimate syllable: always -eis

• e.g. o fóssil → os fósseis, fácil → fáceis

Words ending in ão:

ão > ões, the most common. Majority of feminine nouns, all feminine nouns for actions/processes e.g. realisation. Some (few) masculine nouns.

• e.g. canção → canções

• similar to «canción» and «chanson»

• in English, similar -tion/-ction endings = ção

ão > ãos

• all feminine/masculine nouns with a written stress on the penultimate syllable

• some nouns with just one syllable

• some nouns + adjectives that are stressed in the last syllable but that do not have the endings -ção, -são, -ssão.

• feminine: a mão > mães

• masculine: orfão > orfãos

Some nouns ending in -s

• some nouns ending in -s that are stressed on the penultimate syllable have the same form for both singular and plural

• e.g. o atlas → os atlas