Introduction Chapter Parts of speech in English language

Prepositional phrases
Prepositional phrases can not be treated as analytical case forms as prepositions preserve the lexical meaning. Prepositions may precede the genitive case (at the butcher's), besides analytical forms are opposed to synthetical forms. Prepositional phrases & synthetic forms are not opposed, they are often synonymous (government's decision = the decision of the government). So, there are only two cases but this two-case theory is open to criticism, 's is not a typical case inflexion, it is used' both in the singular & in the plural (man's -men's), it can be added to adverbs (yesterday's meeting), it can be added to phrase {Mary & John's father).
Professor Vorontsova does not recognize case as a morphological category She treats 's as a postposition, a sign of syntactic dependence, as a syntactic form, word resembling preposition.
Academician Smimitskiy also expresses doubts for the recognition of the genitive case but most scholars find that peculiarities of's cannot be denied. Attempts have also been made to combine the case system of nouns & pronouns, thus recognizing three cases: nominative, genitive & accusative (John, him). As stated Bloch the categories of the noun-substitute should reflect the categories of the noun & not vice versa.
A semantico-syntactic approach to case
Finally there is also a semantico-syntactic approach to case where a case is treated as semantic relationship. Different semantic relations of the noun & the verb are treated as "deep semantic cases" which have different forms of expression in the surface (or syntactic) structure. Thus, sentences: John opened the door with the key The door was opened with the key by John. The key opened the door, express the same semantic relations between doer, instrument, object & action. She is eager to please. She is easy to please. Syntactic structure is the same but meaning is different.
Possessive case is narrower in meaning than genitive case. In Old English genitive case could be used with living beings but not with inanimate nouns. Today possessive case may express not only the idea of possession but the idea of subject, object, material, measure, part of the : whole. There is a very old theory that's is a kind of abbreviation of pronoun "his". First it was used with masculine gender, then it spread to feminine as well: II. it doesn't blend with the stem of the word III. it expresses only case but not gender In Modern English possessive case has several specific meanings portraitive meaning (A portrait of the king - king's portrait; He is father of the first husband of my wife). Today we use possessive case not only with the names of living beings but with abstract notions expressing distance, months, seasons & such words as town, city, ocean, sea, world.