先看看上期几个句子的译法：
- 我在考虑这个建议是否值得尝试。（worth）
I am considering if this suggestion is worth trying.
- 我不理解的是他从哪里得到的消息。(understand)
I don't understand where he got thenews.
或者，我们把“是”也译出来，即is。这样“我不理解的”就是句子主语，也要用从句形式，即：
What I don't understand is where he got the news.
- 这个帝国是如何四分五裂的仍不为我们所知。（It）
我们分两步来完成：
How the empire fell apart remains unknown to us.
要求使用it，那就是说主语从句太长，放到后面——
It remains unknown to us how the empire fell apart.
- 我和他在年龄和家庭背景上相似，我想这就是为什么我们成为好朋友的原因。(similar)
I resemble him in age and family background, and I think (that) this is why we can become close friends.
- 这个年轻人是如何在短短半年里掌握了三种语言，引起了听众的极大兴趣。（It）
参照第3句的做法，最终结果是：
It aroused the audience's interest how this young man could master three languages in only half a year.
有没有发现：这几个句子中的“名词从句”，连词都不是that。也就是说，名词从句的连词，不仅仅是that，还有几个——
这就是今天的内容：关于“疑问句改装的名词从句”
典型的名词从句是外加连接词that，表示“那件事情”(that thing)。另外，以疑问词(who、what、when等)引导的疑问句，也可以改装成名词从句，代表一个问题(the question)。例如：
1. I know the question.
S V O
什么问题呢？
2. Who are you?
也即是：
→I know who you are.(我知道你是谁。）
S V O
例2中Who are you?只要改写为非疑问句的顺序who you are，即成为名词从句，以疑问词who当连接词用，不必再加连接词，直接把这个从句放入例1中the question的位置，作为know的宾语，即成为(A)的复句。
再看一个例子：
1. The question is anybody's guess.
S
2. When will the bomb go off?
→ When the bomb will go off is anybody's guess.
S
(炸弹什么时候会爆炸没有人知道。）
例2的疑问句只要改成非疑问句的顺序when the bomb will go off 就成了代表一个问题的名词从句，可以直接放入例1的主语位置构成(A)的复句。
特殊疑问句的疑问词就起到连词的作用。
那，还有一个“一般疑问句（Yes-No回答的那种）”，如果也作为名词从句呢？
这时候，就出来另外两个连词——whether，和 if。
疑问句改装的名词从句中比较特别的，是由whether引导的名词从句。whether并不能独立当做疑问词来引导一个带问号的疑问句，可是它可以引导代表一个问题的名词从句，请看下例：
1. I can't tell.
S V
我傻傻分不清——分不清什么呢？
2. Is he telling the truth？
他是否在说实话？
→(A) I can't tell whether he's telling the truth or not.
O
(我不知道他有没有说真话。）
(A) 中的whether也可以改成if:
I can't tell if he's telling the truth or not.
whether 和if 解释为“是否”。在大多数的情况下可以互换使用，但是在句首位置以及介系词后面就只能用whether。
结语
名词从句有两种形态：
一、完整的简单句外加无意义的连接词 that，代表“那件事””。
二、疑问句改装，疑问词即连接词，代表“那个问题”；其中 whether 有时可改为if，表示“是否”。
名词从句属于名词类，要放到主要从句中的名词位置（主语、宾语、补语、同位语）使用。
以上就是了解名词从句的重点。
下一章要讲副词从句，这是比较单纯的一种复句，可是它的简化变化最为复杂,所以要把基础打好，遇到简化从句变化时才能处理。
巩固一下：
1. I don't know ____ we each have a destiny, or ____ we're all just floating around accidentally—like on a breeze.
2. All of life is an act of letting go, but ______ hurts the most is not taking a moment to say goodbye.
3. I figure life is a gift and I don't intend on wasting it. You never know _____hand you're going to get dealt next. You learn to take life as it comes at you.
4. Life was like a box of chocolates, you never know _____ you're gonna get.
5. Yesterday is history. Tomorrow is a mystery. But today is a gift. That is _____ it’s called the present (the gift). （“Kung Fu Panda”）
6. I have no idea what this life is gonna look like, but I know ______ it has the both of us in it, and I choose us. （“NottingHill”）
7. You're waiting for a train, a train that will take you far away. You know _____ you hope this train will take you, but you can't know for sure. But it doesn't matter, not tell me why—because we'll be together.
8. DNA decides what we are, but not ______ we are. What we are never changed, but who we are never stop changing.
9. I love waking up in the morning and not knowing what's going to happen, or _____I'm going to meet, _____ I'm going to wind up.
