【名词性从句练习题】在英语语法中，名词性从句是构成复杂句子的重要部分。它们可以充当主语、宾语、表语或同位语，使语言表达更加丰富和准确。为了帮助大家更好地掌握这一语法点，以下是一些关于名词性从句的练习题，并附有详细解析与答案。
一、练习题
| 题号 | 句子 | 空格处应填入的引导词 | 正确句子 |
| 1 | I don't know ______ he is coming. | ______ | I don't know whether he is coming. |
| 2 | The teacher asked ______ we had finished the homework. | ______ | The teacher asked if we had finished the homework. |
| 3 | She believes ______ the earth is round. | ______ | She believes that the earth is round. |
| 4 | It's a mystery ______ he left so suddenly. | ______ | It's a mystery why he left so suddenly. |
| 5 | They are discussing ______ we should go on vacation. | ______ | They are discussing where we should go on vacation. |
| 6 | He told me ______ he would come back tomorrow. | ______ | He told me that he would come back tomorrow. |
| 7 | The question is ______ we can finish the project on time. | ______ | The question is whether we can finish the project on time. |
| 8 | I wonder ______ she is late again. | ______ | I wonder why she is late again. |
| 9 | Please tell me ______ you want to eat for dinner. | ______ | Please tell me what you want to eat for dinner. |
| 10 | That is ______ I saw her yesterday. | ______ | That is where I saw her yesterday. |
二、总结
名词性从句主要包括四种类型：主语从句、宾语从句、表语从句和同位语从句。它们通常由连接词（如 that, whether, if, what, where, why 等）引导。
- that 引导的从句常用于表示陈述事实，不作成分。
- whether / if 用于引导选择性疑问句，表示“是否”。
- what / where / why / when / how 等引导特殊疑问句，作从句中的成分。
- who / whom / whose 等也可引导名词性从句，表示人。
在使用时要注意语序为陈述语序，且不能省略引导词（除 that 在某些情况下可省略外）。
通过以上练习题和解析，希望你能更清晰地理解名词性从句的用法和结构。多加练习，提升语感，是掌握这一语法点的关键。
