新sat语法中的关于逗号的考点是最常见的，那么今天我们来讨论一下逗号的用法。
1. 逗号：用于连接一个句子中的并列成分
例句：The main products of the district are wool, cotton, timber and tung-oil.
The little girl likes to sing, to dance, and to act.
必记公式：a and b(两个名词短语平行不用逗号)
a, b, and c
a, b, c, and d
真题讲解：
新SAT OG-T1-Q4：Whey to Go
Yogurt manufacturers, food [Q4] scientists; and government officials are also working together to develop additional solutions for reusing whey.
Question 4
A. NO CHANGE (scientists; and)
B. scientists: and
C. scientists, and
D. scientists, and,
本题中，yogurt manufacturers, food scientists与government officials是并列成分，按照我们的标点公式：a, b, and c, 正确答案为C。
2. 逗号：用于分隔插入语(同位语，非限，状语从句等)
例句：Tom’s sister, a pop singer, will appear at the opening ceremony tonight.
必记公式：S,……, VO.
S, who/which……, VO.
真题讲解：
新SAT OG-T3-Q41：More than One Way to Dress a Cat
The person chosen for this [Q41] task, digital artist, Eldar Zakirov painted the cats in the style traditionally used by portrait artists, in so doing [Q42] presenting the cats as noble individuals worthy of respect.
Question 41.
A. NO CHANGE (task, digital artist, Eldar Zakirov)
B. task, digital artist, Eldar Zakirov,
C. task digital artist Eldar Zakirov,
D. task, digital artist Eldar Zakirov,
第[Q41] 题中，主语是The person chosen for this task, 谓语动词是painted, 插入语部分是digital artist Eldar Zakirov，按照我们的标点公式：S,……, VO. 正确答案为D。
3. 逗号：用于连接词FANBOYS (FANBOYS-for, and, nor, but, or, yet, so )之前
例句：He asked the question in a loud voice, but no one answered.
必记公式： SVO, for/and/nor/but/or/yet/so SVO.
需要特殊注意的是however前后的标点，以下这三种情况都是正确的。
必记公式：
SVO. However, SVO.
SVO; however, SVO.
S, however, VO.
4. 逗号，用于状语从句、介词短语或分词短语后
例句：When the bell rang, the teacher dismissed the class.
(注意，如果状语从句在主句之后，逗号通常省略。例如： The teacher dismissed the class when the bell rang.)
In the ancient palace, they saw the throne where emperors used to sit.
那么，在新SAT的干扰选项里常见错误有哪些呢?
1. 逗号连接两个句子：
SVO, SVO.
I love the film, he loves the food. (错误)
I love the film, and he loves the food. (正确)
I love the film. He loves the food. (正确)
I love the film; he loves the food. (正确)
2. 句子的主语和谓语动词之间加了一个逗号
S, VO.
Few taxpayers received, the much talked-about debate.(错误)
Few taxpayers received, the much talked-about debate. (正确)
S, who/which vo VO
My grandmother, who smokes a lot is ninety. (错误)
My grandmother, who smokes a lot, is ninety. (正确)
“标点很要紧。如果一个人标点不大会用,说明他语言不够清楚。”这是叶圣陶先生曾经强调过的。标点是辅助文字记录语言的一套符号,是文章里不可缺少的组成部分。