手早い答え
chance は可能性、oportunidade は行動に役立つ好機を表すことが多いです。
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
chance
chance or probability
Use chance for the possibility that something will happen, sometimes also a favorable opening.
oportunidade
opportunity
Use oportunidade for a favorable moment or set of conditions for doing something.
選び方
- chance: Choose chance if the sentence points to the possibility that something will happen, sometimes also a favorable opening.
- oportunidade: Choose oportunidade if the sentence points to a favorable moment or set of conditions for doing something.
例文
Há uma boa chance de chuva.
There is a good chance of rain.
Ela recebeu uma oportunidade de trabalho.
She received a job opportunity.
よくある落とし穴
The words overlap in “give someone a chance.” With probability, only chance fits naturally; with a concrete opening, oportunidade is more precise.
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chanceで、もう一度はoportunidade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。