英語 B2レベル 文構造解説
1. 仮定法（第二次条件文・第三次条件文）
第二次条件文
形式: If + 主語 + 過去形, 主語 + would/could/might + 動詞の原形
使用場面: 現在の事実と異なる仮定や、現在の非現実的な状況を表現
例文:
- もし私がお金持ちなら、世界一周旅行をするだろう。
- If I were rich, I would travel around the world.
- もし彼女が時間があれば、私たちと一緒に来るだろう。
- If she had time, she would come with us.
注意点: 「be動詞」は「were」を全ての人称で使うのが正式（If I were...）
第三次条件文
形式: If + 主語 + had + 過去分詞, 主語 + would/could/might + have + 過去分詞
使用場面: 過去の事実と異なる仮定や、過去の非現実的な状況を表現
例文:
- もし昨日雨が降らなかったら、ピクニックに行っていただろう。
- If it hadn't rained yesterday, we would have gone on a picnic.
- もし彼がもっと勉強していたら、試験に合格していただろう。
- If he had studied harder, he would have passed the exam.
2. 混合条件文
形式: 第二次・第三次条件文の組み合わせ
使用場面:
- 過去の事実と現在の結果を結びつける
- 現在の事実と過去の結果を結びつける
例文:
- もし彼が昨日の会議に出席していたら、今日は問題を理解しているだろう。
- If he had attended the meeting yesterday, he would understand the problem now. (過去→現在)
- もし彼女が医者だったら、昨日の緊急事態に対応できていただろう。
- If she were a doctor, she would have been able to respond to yesterday's emergency. (現在→過去)
3. 非限定用法の関係詞節
特徴: カンマで区切られ、追加情報を提供する（省略可能な情報）
使用例:
- 限定用法: The book which is on the table is mine. （テーブルの上にある本は私のものです。）
- 非限定用法: My book, which is on the table, is very interesting. （私の本はテーブルの上にありますが、とても面白いです。）
関係代名詞の使い分け:
- who: 人を先行詞とする
- Dr. Smith, who has worked here for 20 years, is retiring next month.
- which: 物や動物を先行詞とする（thatは非限定用法では使わない）
- This hotel, which was built in the 19th century, has a fascinating history.
- whose: 所有関係を示す
- The professor, whose research has been widely published, gave an inspiring lecture.
- where: 場所を先行詞とする
- Paris, where I studied for a year, is my favorite city.
4. 間接話法（複雑な文、報告動詞）
複雑な文の間接話法
基本変換: 時制の後退、代名詞の変更、時・場所の表現の変更
例文:
- 直接話法: She said, "I will give you the report when I have finished it."
- 間接話法: She said (that) she would give me the report when she had finished it.
様々な報告動詞
- advise（アドバイスする）: He advised me to take regular breaks.
- warn（警告する）: The doctor warned me not to eat too much sugar.
- suggest（提案する）: She suggested going to the museum.
- admit（認める）: He admitted (that) he had made a mistake.
- deny（否定する）: She denied stealing the money.
- promise（約束する）: He promised to call me tomorrow.
5. 受動態（全時制、助動詞を伴うもの）
様々な時制の受動態
- 現在形: The house is cleaned every week.
- 現在進行形: The house is being cleaned now.
- 現在完了形: The house has been cleaned.
- 過去形: The house was cleaned yesterday.
- 過去進行形: The house was being cleaned when I arrived.
- 過去完了形: The house had been cleaned before the guests arrived.
- 未来形: The house will be cleaned tomorrow.
- 未来完了形: The house will have been cleaned by next week.
助動詞を含む受動態
- can/could: The problem can be solved easily.
- must/have to: The form must be filled in completely.
- should/ought to: This medicine should be taken after meals.
- might/may: The project may be delayed due to bad weather.
報告構造
- It is said that...: It is said that the castle is haunted.
- He is thought to...: He is thought to be the best candidate for the job.
- They are believed to have...: They are believed to have left the country.
- She is known to...: She is known to work very hard.
ポイント:
- 行為者が不明または重要でない場合に使用
- 行為を強調したい場合に使用
- 客観的・学術的な文章でよく使われる