A. 定義：一個名詞子句是一個非獨立子句，整個子句當作一個名詞用，通常會是一個獨立子句的一部份。常會是句子的主詞會受詞。也會放在特定形容詞與名詞的後面。

種類：名詞子句有that子句，if/whether子句，疑問詞子句三種。

1.that子句：由that帶領的子句，語意清楚時可以省略that，然而假如that在句首時一定不能省。

位置：that子句的位置可放在不同的地方

a.     在獨立子句的最前面當主詞

That Earth is getting warmer is certain.

b.     在獨立子句的動詞後面當受詞

The catalog states that science courses requires laboratory period.

c.     在特定形容詞後面。如：happy, glad, proud, pleased, upset, worried, certain, surprised, sure等。

The class was surprised that the instructor canceled the final exam.

d.     在特定名詞後面。如：idea, theory, thought, claim, assertion, statement, belief, notion, opinion等。

No one believed Galileo’s theory that Earth revolves around the sun.

e.     將名詞子句放在句首對英語系人士來說不是很自然，所以常會把that子句在句首的改為一個由it帶領的句子，而常會是被動語態，尤其在學術寫作時。然而也可以是主動語態。

It is certain that Earth is getting warmer.

It is believed that carbon dioxide is responsible for global warming.

It has been proven that the world’s deserts are expanding.

Many scientists believed that carbon dioxide is responsible for global warming.

2. If/Whether子句：

以if 或 whether為首的子句。Whether比if正式。or not可加在whether子句之後或whether子句句尾，不能加在if後面，但可以加在if子句的句尾。

The patient wanted to know whether Dr. Chen practices acupuncture.

The patient wanted to know whether or not Dr. Chen practices acupuncture.

The patient wanted to know whether Dr. Chen practices acupuncture or not.

The patient wanted to know if Dr. Chen practices acupuncture.

The patient wanted to know if Dr. Chen practices acupuncture or not.

Whether/If子句是一個陳述，而非問句，所以不能有助動詞。假如是從Yes/No問句改過來時，必須把詞序從疑問句改為陳述句。注意動詞的變化與助動詞的省略。

Is the test easy?

The students want to know if the test is easy.

Does he know the answer?

I want to know whether he knows the answer.

3. 疑問詞子句：

疑問詞子句是用疑問詞如who, what, when, where, why, how much, how等所帶領的子句。疑問副詞可能為子句的主詞，或為非主詞。假如疑問副詞為主詞，則不須改詞序，然而假如非主詞時，必須將詞序從疑問句改為陳述句的句型，省略必要的助動詞，或改變動詞。

The police do not know who committed the robbery.

The police do not know when the robbery happened.

What time is it?

Please tell me what time it is.

How did the robbers enter the apartment?

The police want to know how the robbers entered the apartment.

How did the robbers enter the apartment?

The victims did not know how the robbers had entered the apartment.

注意事項：

1. 名詞子句的前後一定沒有逗號。

2. 名詞子句不會影響句子的標點符號，假如句子為陳述句，則其後加句號，疑問句則加問號。