's 的词源

这个后缀用于构成大多数现代英语名词的属格或所有格单数形式。在中古英语中，它的使用逐渐从古英语的 -es 扩展而来，这在古英语中是阳性和中性名词最常见的属格变化形式（例如 dæg 意为“日”，其属格形式为 dæges，即“日的”）。在发音上，"-es" 这个形式在摩擦音后仍然保留。

古英语中，属格形式还包括 -e、-re、-an 等变化，以及“变音属格”（例如 boc 意为“书”，复数形式为 bec）。而 -es 形式在复数中从未使用（复数中通常使用 -a、-ra、-na），这避免了像 kings' 这样的歧义。

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的拼写通常都是 es。当 e 在发音和书写中被省略时，人们逐渐形成了在所有格单数中用撇号代替丢失的 e 的习惯，以便与复数形式区分开来。后来，这个撇号被视为所有格的标志，并被延续到复数中，但拼写上放在 s 后面，以区分复数和所有格单数。经过大众的理解，这个 's 被认为是 his 的缩写，甚至在某些情况下，his 形式真的被“恢复”了。[Samuel C. Earle, et al, "Sentences and their Elements," New York: Macmillan, 1911]

作为某些副词的后缀，它代表古英语阳性和中性名词及部分形容词的属格单数结尾。