逗号
在用逗号时，有几种基本规则，但逗号的用法其实还有很多种语，像是用逗号来添加句子的意思或强调某件事情丶要点或意义。
虽然老师常这么教：逗号是用来方便我们在句中有「呼吸的空间」。但更精确的说法，是用来组织多个想法或逻辑。另外，先不论文法上的规则，多数人总会在句中加逗号来确保意思有表达清楚；而有时如果句子没逗号也不会影响意思，就乾脆不加逗号。
在列举的片语丶字词或子句之间做分隔
在列举事物时，一般会用逗号来分隔各项事物。但列举到最後两项事物时，通常会在倒数第二项的字尾标上逗号，再接「and」或「or」来举出最後一项。这种逗号在编辑的术语中，叫做「牛津逗号」。
一系列的独立子句（多个句子）
举例
- I met Harry, we went for a swim together, and afterwards Harry went home.
- I like your son, I might even love him, but he is not a very good soccer player.
一系列的名词
举例
- For dinner I had soup, fish, chicken, dessert, and coffee.
- This afternoon I went to Oxford Circus, Picadilly, Hamstead, and Gatwick Airport.
一系列的形容词
列举一系列的形容词时，通常也会用上逗号。然而，如果形容词是在修饰别的形容词，则不必以逗号分隔（请见第三个例句）。
举例
- She was young, beautiful, kind, and intelligent.
- The house we visited was dark, dreary, and run-down.
- She was wearing a bright red shirt.
一系列的动词
举例
- Tony ran towards me, fell, yelled, and fainted.
- The boy leapt, spun, twisted, and dove into the water.
一系列的片语
举例
- The car smashed into the wall, flipped onto its roof, slid along the road, and finally stopped against a tree.
- The dog leapt into the air, snatched the frisbee in its mouth, landed, and ran off into the forest.
添加额外的信息
用逗号来添加非限定关系子句或非必要性的细节或评论，在嵌入的子句前一个字的字尾还有子句的句尾，都会加上逗号。
举例
- China, one of the most powerful nations on Earth, has a huge population.
- Jason's grandmother, who was born in 1930, lived through the Second World War.
- Cats, unlike dogs, do not respect their masters.
- My friend, Jim, likes to go scuba diving.
分词片语
举例
- Hearing that her father was in hospital, Jane left work immediately.
- Walking to the bus stop that morning, Sam knew it was going to be a special day.
附加问句
举例
- She lives in Paris, doesn't she?
- We haven't met, have we?
插入的词语
举例
- Yes, I will stay a little longer, thank you.
- No, he isn't like other boys.
- Wait, I didn't mean to scare you.
最後的小提醒
如果把逗号加在错误的地方，可会导致整个句子的意思不同。观察这两个句子吧：
I detest liars like you; I believe that honesty is the best policy. = 我憎恨像你一样的骗子。
I detest liars, like you; I believe that honesty is the best policy. = 你跟你一样都憎恨骗子。