恒星英语:(口语)Low-levelEnglighlearningLesson1

　　Grammar Points 语法重点　　本课介绍由疑问词引导的名词从句之形成及其用法，以及表示‘第一点’、‘第二点’等序数词的用法。　　It depends on how you study it.　　那要看你如何去学习。　　上句中，how you study it 是疑问词引导的名词从句。此类名词从句均由疑问词（what, when, who, how, why, where等）引导的问句转变而成，兹就其形成及用法分述如下：　　a. 疑问句如何转变为名词从句：　　1) 问句有be动词时：　　主语与be动词还原，前面保留疑问词。　　例：Where is she?-->where she is　　2)问句有一般助词时：　　主语与助词还原，前面保留疑问词。　　例：When will you leave?-->when you will leave　　3)问句有do/does/did等助词时：　　此类疑问句变成名词从句时，先保留句首的疑问词，再将do/does/did去掉，其后的原形动词则按主语人称 及时态作变化。　　例：Where does he live?-->where he lives　　What did you buy?-->what you bought　　[注意]在疑问句中，若疑问句代词who/what/which作主语，则疑问句变成名词从句时，句子结构不变。　　例：Who will go?-->who will go　　What happened?-->what happened　　Which was bought?-->which was bought　　由于上述得知，本文中how you study it乃由How do you study it?变化而成。　　b. 名词从句的功能：　　名词从句应被视作名词，故与名词一样，在句中可作主语、宾语，或置于be动词后作主语补足语。　　1）作主语　　例：Where he lives remains a mystery. 他住在哪里仍是个谜。　　[注意]名词从句作主语时，往往会形成主语过大的现象，因此可用虚主语it代替，置于句首，而被代替的名词从句置于句尾。故上列例句可写成：It remains a mystery where he lives.　　2）作宾语　　例：I don't know why she is crying.　　I didn't pay attention to what you are saying.　　3）置于be动词后作主语补足语　　例：The problem is how we can get there.　　...First, don't be afraid to make mistakes...Second, you must not be shy.　　首先，别怕出错。其次，千万不要害羞。　　上列句中，First及Second为序数词。分别表示“第一，首先”及“第二点，其次”的意思，用于陈列重点或陈述概念、想法时。　　例：When you are at the beach, play safe. First, don't swim too far out. Second, don't swim immediately after eating.　　当你在海滩的时候，要以安全为上。首先，不要游得太远。其次，吃完东西后不要马上游泳。　　[注意]　　a. First/Second/Third...亦可改用Firstly/Secondly/Thirdly...替代。另外，First亦可等于First of all，但无Second/Third...of all的用法。故上列例句亦可改为：When you are at the beach, play safe. Firstly, don't swim too far out. Secondly, don't swim immediately after eating.　　b. 常常有些人会将at first与first混为一谈，但这是错误的。at first使用于一般过去时中，用以叙述过去的状态，表“起初”之意，而first则用以强调次序的概念，故两者用法不同。in the end则表“最后”，常与at first搭配使用。　　例：At first, the new student felt out of place. In the end, he became one of us.　　起初，那个新来的学生觉得格格不入。最后，他和我们打成一片。