手早い答え
feriado は祝日一日、férias は休暇期間です。
確実な見分け方は、英語から訳す前に、その単語の働きを見きわめることです。
それぞれの単語の働き
feriado
public holiday
Use feriado for one officially recognized day when work or school may stop.
férias
vacation or school break
Use férias for a longer period away from work or classes.
選び方
- feriado: Choose feriado if the sentence points to one officially recognized day when work or school may stop.
- férias: Choose férias if the sentence points to a longer period away from work or classes.
例文
A segunda-feira é feriado nacional.
Monday is a national holiday.
Vou viajar nas férias.
I am going to travel during my vacation.
よくある落とし穴
Férias is normally plural in Brazilian Portuguese, even when referring to one vacation period.
文脈の中で練習する
自分の実生活から文を一つ選び、二回書いてみましょう。一度はferiadoで、もう一度はfériasで。どちらも成り立ちそうなら、意味の違いを言葉にしてみましょう。