説明
Use "for" with a length of time. Use "since" with the start of the time. We usually use them with the present perfect.
For example, "I have lived here since 2020." In this sentence, "I" is the subject, "have lived" is the present perfect verb, "here" is the place, and "since 2020" gives the starting point. The meaning is that I started living here in 2020 and I still live here now. Japanese often says "2020年から" or "3年間" with one expression, but English chooses "since" for a starting point and "for" for a period.
「for」は、どれくらいの長さかを表します。「since」は、いつ始まったかを表します。ふつうは現在完了と一緒に使います。
例えば "I have lived here since 2020." では、"I" が主語、"have lived" が現在完了の動詞、"here" が場所、"since 2020" が始まりの時点です。意味は「2020年に住み始めて、今もここに住んでいる」です。日本語では「2020年から」「3年間」のように言えますが、英語では始まりなら "since"、期間なら "for" を使います。
例文
- I have lived here for three years. 私はここに3年間住んでいます。
- She has worked here since 2021. 彼女は2021年からここで働いています。
- We have known each other for a long time. 私たちは長い間お互いを知っています。
- Have you been sick since Monday? 月曜日からずっと具合が悪いですか。
- He has not called me for two days. 彼は2日間電話をくれていません。
- They have waited here since 9 a.m. 彼らは午前9時からここで待っています。
よくある間違い
Japanese learners often use "since" with a period of time.
Wrong: "I have lived here since three years."
Right: "I have lived here for three years."
Use "since" only with a starting point, like "since 2021" or "since Monday."
日本語の「3年間」の感覚で、期間に "since" を使ってしまうことがよくあります。
誤り: "I have lived here since three years."
正しくは "I have lived here for three years."
"since" は「2021年から」「月曜日から」のように始まりの時点だけに使います。