Comment by kazinator

English sentences with pronouns can show that cases exist in English, rather than that they don't.

Without cases "she gave her number to him" becomes "she gave she number to he".

Yet, that is precisely what we have when we substitute concrete names for the pronouns, except for the possessive: "Alice gave Alice's number to Bob".

Pronoun cases and possessives convey the flavor of what it's like to use a language with full-blown case. You just have to use your imagination: what if all the nouns have cases, and there are six or seven of those cases.

More cases means that, for instance, rather than one "her" word that can be used as "give to her", "do to her", "her number", "go with her" , the language will have different declensions.