's
后缀，用于大多数现代英语名词的属格或所有格单数形式； 它的使用逐渐从古英语 -es 扩展而来，这是大多数阳性和中性名词的最常见的属格变化（例如 dæg “日”，属格 dæges “日的”）。在 sibilant 后保留“-es”发音。
古英语还有 -e， -re， -an 的属格，以及“mutation-genitives”（boc “书”，复数 bec），而 -es 形式从未用于复数（-a， -ra， -na 占优势），从而避免了像 kings' 这样的词的动词歧义。
In Middle English, both the possessive singular and the common plural forms were regularly spelled es, and when the e was dropped in pronunciation and from the written word, the habit grew up of writing an apostrophe in place of the lost e in the possessive singular to distinguish it from the plural. Later the apostrophe, which had come to be looked upon as the sign of the possessive, was carried over into the plural, but was written after the s to differentiate that form from the possessive singular. By a process of popular interpretation, the 's was supposed to be a contraction for his, and in some cases the his was actually "restored." [Samuel C. Earle, et al, "Sentences and their Elements," New York: Macmillan, 1911]
在中古英语中，所有格单数和普通复数形式都经常拼写为 es，当 e 在发音和书写中被省略时，习惯上在所有格单数中写一个撇号以区别于复数。后来，撇号被视为所有格的标志，并被引入到复数中，但是在 s 之后写以区分该形式与所有格单数。通过一种流行解释的过程， 's 被认为是 his 的缩写，并且在某些情况下， his 实际上被“恢复”。[塞缪尔·C·厄尔等，“句子及其元素”，纽约：麦克米兰，1911年]
作为一种后缀形式的一些副词，它代表古英语阳性和中性名词以及一些形容词的属格单数结尾。