准备了许久ACT备考的同学们有没有发现逗号在其中所发挥的作用，逗号经常会容易被大家忽略，但是它确是ACT考点之一。接下来小编就为大家介绍ACT考试中逗号的的特点和用法。
(1) 逗号的间隔作用
逗号常用来间隔两个或两个以上的并列成分，但是逗号更重要的考点在于逗号的单独使用，以及逗号与连词连用。关于逗号的使用方法因人而异，因地而异。在这里会给大家罗列出在SAT&ACT考试当中逗号的正确用法。
EX) She came，he did not.(X)
—> She came，but he did not.(O)
EX) The new virus is alleged to have an unprecedented rate of spreading，and the news that shocked the city government.(X)
—> The new virus is alleged to have an unprecedented rate of spreading，the news that shocked the city government.(O)
(2) 序列逗号又名牛津逗号：常见于SAT&ACT
并列的三个或三个以上的词、词组或从句都要用逗号分隔开。每两个成分之间都要有一个逗号，在最后一个成分之前要加上and。在and前的逗号叫做序列逗号又名牛津逗号。尽管很多学校认为加上序列逗号没有必要，而且很多报纸和杂志通常不使用序列逗号，但是在SAT&ACT考试当中，同学们一定要注意加上序列逗号。
EX) He teaches Japanese，Chinese and English.(X)
—> He teaches Japanese，Chinese，and English.(O)
EX) The lion saw another lion，confirmed it was a male and fought it.(X)
—> The lion saw another lion，confirmed it was a male, and fought it.(O)
(3) 两个独立句子结合时逗号的使用问题
如果两个独立的句子要结合在一起，我们需要用一个逗号+并列连词(and，but， or， nor，so，for，yet)的形式。但是如果两个句子的主语相同，可以省略第二个句子的主语成分，这时就不需要加逗号直接使用并列连词即可。
EX) Cathy earned a lot of money but her mother got sick soon.(X)
—> Cathy earned a lot of money，but her mother got sick soon.(O)
—> Cathy earned a lot of money and spent it for pleasure mostly.(O)
(4)两个短语结合时逗号的使用问题
如果仅仅是两个短语结合而不是句子，那么就不需要使用逗号。
EX) With heat，and long working hours，they gradually got exhausted.(X)
—> With heat and long working hours，they gradually got exhausted.(O)
(5)连词之后逗号的使用问题
逗号不可以用在连词之后。
EX) Roger wanted to study more but， his mother told him to go to sleep.(X)
—> Roger wanted to study more，but his mother told him to go to sleep.(O)
(6)分词结构与逗号的使用问题
如果句子是含有非谓语动词的独立结构需要用逗号将独立结构与主句分开，表明独立结构的逻辑主语与主句主语一致。
EX)Lin offered a chance to make money to Kim，working in the pyramid organization.
Working in the pyramid organization，Lin offered a chance to make money to Kim.
EX) Lin offered a chance to make money to Kim working in the pyramid organization. Lin给在金字塔组织工作的Kim提供了一个赚钱的机会。
(7)同位语与逗号的使用问题
同位语经常被看作插入语，当在名词之后加上同位语并且同位语对名词起解释或补充说明的作用时，同位语的前后都有逗号。但是,当同位语放在名词之前时，就不需要用逗号隔开，因为在这种情况下同位语相当于形容词。
EX) Bruce English archaeologist went to Singapore.(X)
—> Bruce，English archaeologist，went to Singapore.(O)
EX) English archaeologist， Bruce went to Singapore.(X)
—> English archaeologist Bruce went to Singapore.(O)
EX) My math teacher，Mr. Hu’s aim school’s average score over city’s can be difficult.(X)
—> My math teacher Mr. Hu’s aim，school’s average score over city’s，is impossible.(O)
(8)从属连词与逗号的使用问题
当状语从句前置时，主句与从句之间应用逗号隔开。但是当状语从句在主句之后时，就不需要使用逗号了。
EX) If you text while driving you will have difficulty concentrating.(X)
—>If you text while driving，you will have difficulty concentrating.(O)
EX) You will have difficulty concentrating，if you text while driving.(X)
—>You will have difficulty concentrating if you text while driving.(O)
EX) Shawn did not want to see the test result，because he was afraid.(X)
—> Shawn did not want to see the test result because he was afraid.(O)
(9)形容词的并列与逗号的使用问题
当形容词并列使用时，用逗号代替并列连词将形容词隔开，且形容词之后必须有需要修饰的名词。
EX) She was a thin and agile athlete. = She was a thin，agile athlete.
EX) Ricky’s room was dark，mysterious.(X)
—>Ricky’s room was dark and mysterious.(O)
(10)引用部分与逗号的使用问题
句子中被引用的部分要用逗号隔开。如果引用的句子被分开使用，要用逗号表明哪一部分是主句，哪一部分是被分开的引语。
(11)对比短语与逗号的使用
两个意思相反的短语之间要用逗号隔开。
EX) The movie was filmed in China not in Japan.(X)
—> The movie was filmed in China, not in Japan.(O)
EX) Matt was angry with his brother not with his friends.(X)
—> Matt was angry with his brother, not with his friends.(O)
(12)关系代词前加逗号的问题
1) 当关系代词前有逗号时，从句要表达对主句内容，或先行词的补充、解释或附加说明。
主句与先行词或从句之间一般用逗号分开，常常单独翻译。没有从句，主句意思仍然完整。
EX) He has two sons who became doctors.
这里who became doctors修饰two sons 他有两个儿子成为了医生。(他可能有好几个儿子，但是只有两个成为了医生)
EX) He has two sons，who became doctors.
这里who became doctors是对前面他有两个儿子进行修饰。
= He has two sons, and they became doctors. 他有两个儿子, 都成为了医生。
2) 逗号不能放在that之前
EX) The car，that he bought，got recalled.(X)
—>The car，which he bought，got recalled.(O)
—> The car that he bought got recalled.(O)
他买的车被召回了。
3) 当人名出现在关系代词之前时经常用逗号隔开
EX) Ashland，who played the song，is my roommate.
(13)逗号在其他情况下的使用问题
1)使用逗号能够使句子表意更清晰
EX) Outside the square was crowded with people who were waiting for the New Year.
EX) Outside，the square was crowded with people who were waiting for the New Year.
2)在城市、州、省的名字之间要用逗号隔开
EX) Dalian，Liaoning
EX) Boston，Massachusetts
3)表达时间时逗号的固定使用位置
在日与年之间要加逗号。
EX) June 17，1985，was one of the most meaningful days for them.
但是如果时间的表达顺序为日月年，就不需要加逗号。
EX) She was adopted on 19 February 1962.
如果没有注明日期就不需要使用逗号。
EX) Suzy was born in May 2010.
4)SAT&ACT考试中不用when来指代主句所表达的情况，在这种情况下常选用which来做关系代词。
EX) Sandra called the police，which upset Luke even more.( X: Sandra叫警察这件事儿让Luke不高兴)
这句话在国内课堂上很常见，但是在SAT考试当中这句话是错误的表达，因为先行词不明确导致句意模糊。
—> Sandra called the police，upsetting Luke even more.(O: Sandra发出两个动作 calling 和 upsetting)
EX) Han did not come，which disappointed her.(X) Han没来这件事儿让她很失望，这里which指代Han没来这种情况。
以上就是小编为大家介绍的ACT考试中逗号的相关用法，大家可以作为参考。
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