Nouns that are feminine by form
從形式上判斷是陰性的名詞
(i) The vast majority of nouns ending in -a are feminine.
絕大部分以-a結尾的名詞都是陰性的
Exceptions: nouns ending in -a that denote human beings and can therefore be masculine or feminine depending on the sex of the person referred to; a group of nouns ending in -ma, e.g. problema ‘problem’, pajama ‘pyjamas’; the words alerta ‘alert, warning’, cometa ‘comet’, dia ‘day’, mapa ‘map’, planeta ‘planet’, samba ‘samba’, tapa ‘slap’, among others, which just have to be memorized. Note that nouns ending in stressed a (á) are usually masculine, e.g. maracujá ‘passion fruit’, sofá ‘sofa’, tamanduá ‘anteater’, as are those ending in -ã that denote an inanimate object, e.g. balangandã ‘bauble’, divã ‘couch’, o Irã ‘Iran’, although maçã ‘apple’ and lã ‘wool’ are feminine.
例外：以-a結尾的指示人類的名詞，它可以是陽性或者是陰性的，決定于所指向的人物的性別，一些以-ma結尾的名詞，例如，problema ‘problem’‘問題’， pajama ‘pyjamas’ ‘睡衣’， alerta ‘alert, warning’警報，提示，cometa ‘comet’ 彗星, dia ‘day’日子, mapa ‘map’地圖, planeta ‘planet’行星, samba ‘samba’桑巴, tapa ‘slap’ 摑，諸如此類，都是必須要特別記憶的。需要注意的是，那些以重讀(á)結尾的名詞一般都是陽性的，例如. maracujá ‘passion fruit’ 百香果，sofá ‘sofa’,沙發，tamanduá ‘anteater’ 食蟻獸，同樣地，那些以-ã結尾的指示為無生命的物體也是陽性的，例如balangandã ‘bauble’, 小件裝飾品，divã ‘couch’ 睡椅, o Irã ‘Iran’ 伊朗, 盡管maçã ‘apple’蘋果 and lã ‘wool’羊毛是陰性的
(ii) In addition, nouns with the following endings are feminine: -dade,1 e.g. lealdade ‘loyalty’; -ção (corresponding to English -tion), e.g. ação ‘action’; -dão (abstract nouns), e.g. solidão ‘loneliness’; -gem,2 e.g. viagem ‘journey’; -ise, e.g. crise ‘crisis’;-ite, e.g. bronquite ‘bronchitis’; -são (corresponding to English -sion), e.g. decisão ‘decision’; and -tude, e.g. juventude ‘youth’.
除此之外，以下面作為詞尾的名詞都是陰性的
-dade,e.g. lealdade ‘loyalty’;忠誠
-ção (corresponding to English -tion), e.g. ação ‘action’;（那些對應英語-tion結尾的）
-dão (abstract nouns), e.g. solidão ‘loneliness’;抽象名詞，例如，孤獨
-gem,e.g. viagem ‘journey’; 旅程
-ise, e.g. crise ‘crisis’;危機
-ite, e.g. bronquite ‘bronchitis’; 支氣管炎
-são (corresponding to English -sion), e.g. decisão ‘decision’; 決定
-tude, e.g. juventude ‘youth’.年輕時代
1 The word autoridade is used as a masculine noun when it means ‘a (male) government official’.
autoridade通常被用作陽性名詞，當它被意為‘一個男性的政府官員’
2 Except the word personagem ‘character’ (in a book, film, etc.), which can be masculine or feminine.
除了角色（在書或者是電影等），它可以是陽性的也可以是陰性的