case in English

An English noun keeps the same shape whether the phrase it heads is a subject, a direct object or the complement of a preposition, and grammatical role is carried by word order and by the prepositions themselves. The personal pronouns are the exception, and they are not marginal, since they appear in most finite clauses. Seven pairs survive: I and me, he and him, she and her, we and us, they and them, and, for a shrinking set of speakers, who and whom. The neuter third person singular and the second person have levelled entirely and draw no contrast at all, which is worth stating because it means the system is not even complete within the one word class that has it. There are two terms, not four: unlike a language that keeps a separate form after a preposition and a separate dative, English uses one object form for the direct object, the indirect object and the prepositional complement alike.

The record is marked contested because of the possessive marker, and the disagreement is about what kind of thing it is rather than about the facts of its distribution. On one analysis it is a genitive case ending on the noun, which would make English a language with case marking in the noun phrase proper. On the other it is a clitic attaching to the right edge of the whole phrase rather than to any word, and the evidence for that reading is that it lands after the final word of the phrase even when that word is not the possessor, as in a phrase whose head noun is followed by a prepositional modifier. A case ending attaches to a word; this attaches to a boundary. The convention adopted here is the second analysis, and it is recorded as a convention rather than a finding.

The marking is recorded as conditioned because it is confined to one word class, and it is worth saying that even there it is conditioned by position alone: the form is selected by where the pronoun sits, with no semantic contribution of its own.