SAT语法应该是最容易提升分数的一部分了，所以大家在复习备考时候的目标应该是语法部分最多错一个！其中，小曹认为SAT语法，句子结构体是最简单的了！一定一定要做到不出错！！
下面，小曹来讲解一下句子结构题最常见的两种考查形式：Fragments（成分残缺）和Run-on Sentences（run-on 句型）！
成分残缺
铭记法则1：句子结构必不可少的成分就是主语，和可以作为谓语的动词。当然，主系表也是一种结构。但是总归来说，主语+动词+其他句子成分。
我们先来看两个极为简单的句子：
He was tired.
Because he was tired.
大家先来看一下哪个是句子？
答案当然是第一个，因为第二个含有because连词。所以，第二个只是一个fragment。但是这两句话都可以作为从句。一个从句应该包含主语和动词，但一个从句可能是完整的句子，也可能不是。
所以，从句的意义是什么呢？
把长句分解成从句有助于我们更好地理解句子的每一个部分在做什么。这也有助于你知道自己正在阅读的是一个实际的句子，还是Run-on或是一个片段。
现在让我们来看看一个由两个子句组成的句子：Because he was tired, Charlie decided not to run the race.
第一句，“because he was tired”不是一句话。我们称之为从句，因为它不是句子中最重要的部分。因此，它是次要的（知道主次，对于SAT阅读时候碰到的长难句也是很重要的！）“Charlie decided not to run the race.”是这句话的主句，这是这句话的Big Idea！
从句也被称为从属子句，因为它“取决于另一个子句”。否则，它只是一个句子片段。同样，一个完整句子的子句称为独立子句。它是独立的，它不需要依靠任何其他子句作为句子。SAT不会测试你的确切术语，但是它会测试你判断一个句子是否是片段的能力。
接下来我们再看连词，连词连接两个句子。所以又回到了最开始的问题。小曹告诉大家一个小Tip：无论一个句子多长，他有N个连词，必定有N+1个主语！
常见的连词有很多，比如：because, although, even though, since, nevertheless, whereas, while……
以上是两个容易错的点，考试中还会出现很多残缺的句子成分，比如缺主语，缺动词，只有从句形式等等。下面小曹举了几个例句，大家一起看看哪个句子是完整的句子？
1. Though she participated often in class, hoping to get an ‘A’.
2. Hoping to get an ‘A’, she participated often in class.
3. Growing up in a household in which everyone watched baseball, David knowing all of the rules of the game.
4. Because he studied, he passed.
1.残缺成分。前面though开头是一个从句，第二部分是一个片段，没有主语和动词。
2.完整句子，是典型的Doing……，SVO的结构。
3.残缺成分。虽然它与第二句话十分相像，但是需要注意的是，这句话并没有一个“actual”动词。所以，如果把“knowing”变成knew会变成一个有效的句子。
4.完整句子，所有成分都有。大家在备考的时候也要注意，不要觉得句子短就不是句子不敢选！
Run-on
铭记法则2：不要用逗号连接完整句子！
我们都知道两个完整句子之间，要么连词，要么句号，要么分号。用逗号代替句号的行为叫做“comma splice”，这也是大家最常犯的书写错误之一，所以SAT写作的时候一定要注意。
我们先来看例子：
✓ I can’t hear you. Can you please use the megaphone?
✗ I can’t hear you, can you please use the megaphone?
所以解决方案我也提到了：1.分成两个独立的句子。2.使用分号。3.用逗号和连词组成复合句。
铭记法则3：只有“and”是不够的！
使用逗号和and才是正确的用法，同样，对于but，or，so也是这个样子。一起来看例句：
✓ I can’t hear you, so can you please use the megaphone?
✗ I can’t hear you and can you please use the megaphone?
但是这些词名词、动词或形容词的组合。例如：
✓  I bought glow-in-the-dark sunscreen and went to the beach last night.
✗ I bought glow-in-the-dark sunscreen and I went to the beach last night.
除了以上提到的，我们完整的看一下Sentence Structure 句子结构的整体考点：主要考察学生能否识别并改正句子中的错误。
其中包括：
1) Sentence Boundaries 句子完成
识别并改正语法上不完整的句子。
2)Subordination and Coordination 逻辑关联词
识别并改正句子之间使用错误的逻辑关联词。
3) Parallel Structure 平行结构
识别并改正平行结构错误。
4)Modifier Placement 修饰语位置
识别并改正与修饰语有关的错误，包括悬垂修饰语和误置修饰语。
5) Verb Tense, Mood and Voice 动词时态，语气，语态
6)Pronoun Person and Number 人称代词和数
最后，来一起看一道题目：
Searching for Guinevere
Stories of kings and queens have captivated readers for centuries, and arguably, the tales of King Arthur and Guinevere are among the most enchanting. Arthur ruled the kingdom of Camelot, and Guinevere was his queen. But were they real people or fictional characters? The debate has continued for centuries. Though many scholars have found evidence that the legendary Arthur was, at the very least, based on a real person who lived in Britain roughly between 450 and① 500 CE. They continueto search for the historical identity of Guinevere. Guinevere first appeared as King Arthur‘s queen in one of the most widely-studied works of Arthurian literature, ②The History of the Kings of Britain. This bookwas written by Geoffrey of Monmouth around 1135 CE. Geoffrey‘s historical treatment of the legend is often ③sited as evidence that the queen of Camelot existed, as the book chronicles the lives of a number of historical rulers.
Guinevere is identified by Geoffrey as a noblewoman of Roman descent who met King Arthur in the court of Duke Cador of Cornwall, where she lived as a ward.④ In Malory‘s portrayal, Guinevere had no real power as a monarch but served as a kind of spiritual leader, providing guidance and moral support to the knights in their roles as defenders of the kingdom. Le Morte d‘ Arthur was also one of the first works to reference Guinevere‘s romance with the knight, Sir Lancelot. As many Arthurian scholars know, the distinction between history and literature was blurred in the Middle Ages. Consequently, the true identity of Guinevere may never be known with certainty. Yet regardless of whether Guinevere was real or fictional, her story⑤ had endured centuries—and through each retelling, she continues to live on in the imaginations of people around the world.
1
  1. NO CHANGE
  2. 500 CE. Continuing
  3. 500 CE, continuing
  4. 500 CE, they continue
2
Which choice most effectively combines the sentences at the underlined portion?
  1. The History of the Kings of Britain, and this book
  2. The History of the Kings of Britain, which
  3. a book called The History of the Kings of Britain, as this
  4. a book called The History of the Kings of Britain, and this
3
  1. NO CHANGE
  2. insighted
  3. cited
  4.  incited
4
Which choice most effectively sets up the portrayal of Guinevere discussed in the rest of the paragraph?
  1. Three centuries later, however, Thomas Malory painted a very different portrait of Guinevere in Le Morte d‘Arthur.
  2. Sir Thomas Malory was an English knight and Member of Parliament who also wrote extensively about the history of the British monarchy.

  3. Many historians believe that the portrayal of Arthur and Guinevere in Sir Thomas Malory‘s Le Morte d‘Arthur was actually a political commentary on the War of the Roses (1455-1487 CE).
  4. In Le Morte d‘Arthur, Sir Thomas Malory describes an idyllic England under King Arthur and Guinevere, which eventually collapses into chaos and political unrest. E. I would be guessing.
5
  1. NO CHANGE
  2. was enduring
  3. would have endured
  4. has endured
答案分割线
 D B C A D
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