Case
Historically, English used to mark nouns for case, and the two remnants of this case marking are the pronominal system and the possessive clitic (which used to be called the Saxon genitive). The possessive is marked by a clitic at the end of the possessing noun phrase. This can be illustrated in the following manner:

The king's daughter's house fell.

The first <'s> clitic on king indicates that the daughter in question is the king's. The second <'s> clitic does not attach to daughter, as many people mistakenly believe, but in fact to the entire noun phrase The king's daughter.

English preserves the old Germanic noun case system in its pronouns. Their forms vary with gender, number, person, and case. The full set of cases is listed below; note that modern use of the second person singular thou, originally the informal form to the formal you, is very rare, and is confined to dialects and religious and poetic functions. In modern Standard English, the second person plural you is used instead.
Case 1st sg. 2nd sg. 3rd sg. 1st pl. 2nd pl. 3rd pl. interrogative
Nominative I you (thou) he, she, it we you (ye) they who
Genitive mine/my yours/your (thine/thy) his, hers/her, its ours/our yours/your theirs/their whose
Reflexive myself yourself (thyself) himself/herself, itself ourself yourselves themself
Accusative me you (thee) him, her, it us you them whom