English language evolution reveals surprising origins of possessive 's pattern
The development of the 's-genitive in English is not just a leftover from Old English but a mix of two patterns: inflectional genitive endings and the construction "John his book." The rules for using 's in English between 1400 and 1650 are the same as those for the possessive-linked genitive. This idea is supported by looking at other West Germanic languages like Afrikaans.