I. The preposition
II. Basic structure of PPs
Example: PP [early in the morning on Wednesday]
III. Complements and adjuncts in the PP
PPs are constituents whose heads are prepositions. Complements in the PP are most commonly NPs: on [NP Wednesday], but can also be PPs themselves: from [PP under the table].
Example: PP [from [PP under the table]]
Clauses can occur as complements as well, e.g. They argued about [who should clean up the mess]. Note that for some prepositions it has been suggested that they are best treated as COMP elements, i.e. they have the function of a complementizer): I would prefer very much [CP for [IP you to leave]].
Adjuncts while rarer, are also possible: [P' decidely [P' beyond our comprehension]].
PPs commonly appear as adjuncts, e.g. as adverbials of place, time, means, and manner. Examples are in the garden (adverbial of place), on Monday (adverbial of time), with a knife (adverbial of means), in a strange way (adverbial of manner).
These PPs are all adverbials, i.e. they are structurally PPs but serve a semantic function similar to Adverb Phrases (AdvPs); cf. in a strange way (PP) and carefully (AdvP).
Note that certain NPs also serve an adverbial function: She goes [NP next year], They agreed to meet [NP Monday morning].
PPs can also occur as complements of verbs (e.g. [PP to John] in He gave the book to John or [PP in London] in He lives in London.), as complements of nouns (e.g. [PP of English] in teacher of English or [PP on Syntax] in exercises on Syntax, as complements of adjectives (e.g. [PP about the meeting] in excited about the meeting, or as complements of other prepositions (as illustrated in the example from under the table, see above).
IV. Specifiers in the PP
Specifiers in the PP include such degree expressions as just, quite, right, and so.
In the text above we refer to constituents of the type [determiner + noun] (e.g. the table) as NPs. In a more recent analysis, determiners are considered to be the head (D°) of a determiner phrase (DP), and the noun functions as its NP-complement.
For further information on DPs click here.