在直接引用某人说过的话时，会用到引号。但如果是转述某人说过的话，就不用引号。
举例
- "I'm going to the store now," she said.
- Harry told me, "Don't forget your soccer jersey."
- Harry told me not to forget my soccer jersey.
如果要在引用句中再引用他人的话语，就会用单引号和双引号来区别两句引文。
举例
'I haven't spoken to Peter for months,' Dianne said.'The last time I spoke to him he said, "I'm going to Bahrain and won't be back for about three years", I've heard nothing since then'.
用单引号或双引号来表示谚语或不熟悉的说法
举例
- I've always thought that he was very annoying, a bit of a 'pain in the neck.'
- I'm not sure what you mean by "custodial care", but I'm sure you will explain it to me.
在学术写作上，会用单引号或双引号来标明文献或资料来源。文献引用书写格式有好几种，学术机构一般会有偏好的一种写法，他们有时会在网站或简章上公布指定的格式。
举例
- "The Migration Flight of the Lesser Tweazle", by Jeremey Adams, The Bird Spotter Magazine, July 2009.