The prepositions express primarily notions of space, then notions of time, and finally are used in figurative relations to denote cause, agency, means, manner, etc. Attic often differs from the Epic in using the prepositions to denote metaphorical relations. The prepositions define the character of the verbal action and set forth the relations of an oblique case to the predicate with greater precision than is possible for the cases without a preposition. Thus,
μετὰ δὲ μνηστῆρσιν ἔειπε
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].