問 1
The cake was made ( ) my sister.
- from
- by
- of
- with
be + 過去分詞 + by + 動作主 (典型形)
by + 動作主 = 「〜によって」。受動態で動作の主体を明示するときの基本形。
"The cake was made ~ my sister." は動作の主体を示す = 「by」。受動態の by + 動作主: 能動文の「主語」が受動文では by + 名詞 に変わる。能動 ⇄ 受動 のパラフレーズ: "My sister made the cake." (能動) ⇄ "The cake was made by my sister." (受動)。意味: 「ケーキは姉が作った」━ by my sister が動作の主体 (誰が作ったか) を表す。
「with」
= with は道具/手段 ━ 動作主には by。
「from」
= from は出身/起源 ━ 動作主には by。
「of」
= of は所属/素材 ━ 動作主には by。
| 形 | マーカー | 例 |
|---|---|---|
| by + 人 (動作主) | by my sister, by Tom | Made by my sister. |
| by + 組織 | by the company, by the city | Built by the city. |
| by + 自然 | by the wind, by the rain | Broken by the wind. |
| by + 動物 | by my dog, by the cat | Eaten by my dog. |
| 文型 | 形 | 例 |
|---|---|---|
| 動作主が人 | be + p.p. + by + 人 | Made by my mother. |
| 動作主が組織 | be + p.p. + by + 組織 | Built by the city. |
| 動作主が自然/物 | be + p.p. + by + 物 | Damaged by the storm. |
The cake was made by my sister.
ケーキは姉が作った。
This book was written by a young author.
この本は若い作家が書いた。
The window was broken by the strong wind.
窓は強風で割れた。
My homework was eaten by my dog.
宿題は犬に食べられた。
The painting was done by a famous artist.
絵は有名な画家が描いた。
- by + 動作主の使い方 (3級必修)
★
- 能動 → 受動 の変換ルール
能動 "S + V + O." → 受動 "O + be + p.p. + by + S." ━ ★
- by を省略するケース
① 動作主が不明 "My bike was stolen." (誰が盗んだか不明) ② 動作主が明らかな "Rice is grown in Japan." (農家が育てるのは自明) ③ 一般論 "English is spoken worldwide." (人々が話す = 自明) ━ ★
- by を必ず付けるケース
① 重要な作者・人物 "Hamlet was written by Shakespeare." ② 動作主が特殊 "The cake was made by my 5-year-old son." ━ ★
- by の前置詞代用
一部の動詞 (be known, be made 等) は by 以外の前置詞を使う ━ これが次の問題のポイント