1.连接词+不定式结构

“what，which，when，where，how，whether+不定式”在句子中可以作主语、表语、动词宾语、介词宾语和同位语。

(1)作主语。

How to prevent them from swimming is a problem．

怎么去防止他们游泳是一个大难题。

Whether to accept the invitation or not is for you to decide．

接不接受邀请看你的。

When to hold the conference depends on the weather．

什么时候举行会议要视天气而定。

(2)作表语。

The problem is where to meet him．

问题是到哪里去见他。

But the question was how to deliver it to Nome fast．(人教大纲版高三第53页)

可是问题是怎样才能很快地把它发到诺姆来。

(3)作动词宾语。

When we choose what to buy and eat，we had better think whether the food will give us the nutrients we need．(人教大纲版高一下第3页)

我们选定买什么、吃什么的时候，最好考虑一下该食品是否能提供我们所需的营养。

Do you know which topic to choose?

你知道选什么主题吗?

Has he told you in which room to live?

他有没有告诉你住哪间屋子?

The director will help them decide how to move，where to stand or walk and what expressions to use．(人教大纲版高一下第87页)

导演会帮助他们决定动作怎么做，站和走的方位以及使用什么样的表情。

Have you considered how to refuse his invitation?

你有没有考虑过如何拒绝他的邀请呢?

(4)作介词宾语。

He gave me some advice on how to learn English．

有关怎么学习英语，他给我们提出了一点建议。

People struggled for the right to be free in their choice of which god to believe in．(人教大纲版高二下第30页)

人们为争取宗教信仰自由的权利而斗争。

Miss Liu's work opened up a debate about how best to help young people control their use of the Internet，rather than be controlled by it．(人教大纲版高三第261页)

刘女士的研究开启了关于如何最大限度地引导年轻人使用而非沉迷于网络的辩论的大门。

(5)作同位语。

I have no idea what to do．

我不知道该怎么办才好。