在直接引用某人說過的話時，會用到引號。但如果是轉述某人說過的話，就不用引號。
舉例
- "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話語，就會用單引號和雙引號來區別兩句引文。
舉例
'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'.
用單引號或雙引號來表示諺語或不熟悉的說法
舉例
- 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.
在學術寫作上，會用單引號或雙引號來標明文獻或資料來源。文獻引用書寫格式有好幾種，學術機構一般會有偏好的一種寫法，他們有時會在網站或簡章上公布指定的格式。
舉例
- "The Migration Flight of the Lesser Tweazle", by Jeremey Adams, The Bird Spotter Magazine, July 2009.