Unit5语法讲解及习题：宾语从句（that_if_whether引导） -2025-2026学年外研版英语八年级下册

外研英语八下Unit5语法讲解及习题 宾语从句（that/if/whether引导） 一、语法讲解 1. 宾语从句的本质与意义 核心逻辑：在复合句中，充当主句宾语的句子称为宾语从句。 本单元重点学习由 that / if / whether 引导的宾语从句，用于表达观点、疑问或不确定的信息，贴合“自然探索”主题。 2. 核心用法对比表 引导词 含义与用法 适用场景 例句 that 无实际含义，仅起连接作用，可省略 陈述事实、观点或确信的信息 1. People believed that dinosaurs looked like huge lizards. 人们认为恐龙看起来像巨大的蜥蜴。 2. We know that the sun rises in the east. 我们知道太阳从东方升起 if / whether 表“是否”，含义相同，不可省略 表达疑问或不确定的信息 1. They can tell us whether dinosaurs had feathers. 它们可以告诉我们恐龙是否有羽毛。 2. Scientists aren't sure if there is life on other planets. 科学家不确定其他星球上是否有生命。 重点提示： if 和 whether 通常可互换，但在与 or not 直接连用、介词后或不定式前时，只能用 whether。 宾语从句必须使用陈述语序（主语 + 谓语），不能用疑问语序。 3. 用法场景详细解析 (1) that 引导的宾语从句 用于陈述客观事实或确定的观点，that 在口语和非正式文体中常省略。 例：We learned (that) the Sahara is the largest desert in the world. 中文：我们了解到撒哈拉沙漠是世界上最大的沙漠。 (2) if / whether 引导的宾语从句 用于表达疑问或不确定的信息，从句用陈述语序。 例：Scientists want to know whether the ancient forest once existed. 中文：科学家想知道这片远古森林是否曾经存在过。 与 or not 连用时，只能用 whether： 例：We're not sure whether or not the plant can survive in the desert. 中文：我们不确定这种植物能否在沙漠中存活。 (3) 语序规则 无论主句是陈述句还是疑问句，宾语从句都必须用陈述语序。 例： 错误：He asked if where I had been. 正确：He asked where I had been. 中文：他问我去过哪里。 2、 习题 Ⅰ. 用 that / if / whether 填空 1. People believed ___________ dinosaurs looked like huge lizards. 2. Scientists aren't sure ___________ there is life on Mars. 3. I know ___________ the Amazon is the world's largest rainforest. 4. She asked ___________ we would go to the nature museum. 5. They told me ___________ the boiling river is in the Amazon. 6. We want to know ___________ the plant can survive in the desert. 7. He said ___________ he would join the nature exploration team. 8. I wonder ___________ the old tree is over 1,000 years old. 9. The report says ___________ the number of wild tigers is increasing. 10. Please tell me ___________ you need more information about the project. 11. We discussed ___________ we should go camping or visit the zoo. 12. I'm not sure ___________ the weather will be good tomorrow. Ⅱ. 句型转换 1. Is there life in outer space? Scientists aren't sure. → Scientists aren't sure ___________ there is life in outer space. 2. "I want to be a scientist and study plants," John told his parents. → John told his parents ___________ he wanted to be a scientist and study plants. 3. Is Mr Brown interested in insects or birds? Emily wants to know. → Emily wants to know ___________ Mr Brown is interested in insects or birds. 4. The earth goes around the sun. We all know it. → We all know ___________ the earth goes around the sun. 5. Will the rainforest disappear in 100 years? We're worried. → We're worried ___________ the rainforest will disappear in 100 years. 6. "The dinosaurs died out 65 million years ago," the teacher said. → The teacher said ___________ the dinosaurs died out 65 million years ago. 7. Can the plant grow in cold weather? Let's find out. → Let's find out ___________ the plant can grow in cold weather. 8. The Nile is the longest river in the world. We learned it. → We learned ___________ the Nile is the longest river in the world. 9. Did the ancient people live in this cave? The archaeologist is checking. → The archaeologist is checking ___________ the ancient people lived in this cave. 10. The polar ice is melting. It's a fact. → It's a fact ___________ the polar ice is melting. Ⅲ. 单项选择 1. I know ___________ the sun rises in the east. A. that B. if C. whether D. when 2. She asked ___________ we would go hiking this weekend. A. that B. if C. what D. who 3. They want to know ___________ the animal is a new species. A. that B. if C. where D. how 4. He told me ___________ he had seen a UFO in the sky. A. that B. if C. whether D. why 5. I'm not sure ___________ I should take a raincoat or not. A. that B. if C. whether D. which 6. The report says ___________ the air quality has improved. A. that B. if C. whether D. where 7. We discussed ___________ we should visit the museum or the park. A. that B. if C. whether D. what 8. She wondered ___________ the plant could survive without water. A. that B. if C. whether D. both B and C Ⅳ. 情景对话补全 1. A: Do you think ___________ the dinosaurs had feathers? B: Yes, some scientists believe ___________ they did. 2. A: I'm not sure ___________ we can find the rare flower. B: Let's ask the guide ___________ he knows where it grows. 3. A: The teacher said ___________ the Amazon is home to millions of species. B: Really? I didn't know ___________ it was so important. 4. A: Can you tell me ___________ the nature reserve is open on Sundays? B: I think ___________ it is, but I'm not 100% sure. 三、答案与解析 Ⅰ. 填空答案 1. that 2. if/whether 3. that 4. if/whether 5. that 6. if/whether 7. that 8. if/whether 9. that 10. if/whether 11. whether 12. if/whether Ⅱ. 句型转换答案 1. if/whether 2. that 3. whether 4. that 5. if/whether 6. that 7. if/whether 8. that 9. if/whether 10. that Ⅲ. 单项选择答案与解析 1. A — 陈述客观事实，用 that。 2. B — 表达疑问“是否”，用 if。 3. B — 表达疑问“是否”，用 if。 4. A — 陈述观点，用 that。 5. C — 与 or not 连用，只能用 whether。 6. A — 陈述报告内容，用 that。 7. C — 与 or 连用表选择，用 whether。 8. D — if 和 whether 均可。 Ⅳ. 情景对话补全答案 1. whether/if; that 2. whether/if; if/whether 3. that; that 4. if/whether; that ( 1 ) 学科网（北京）股份有限公司 $