A Student's Introduction to English Grammar

§3.1 Prepositions vs adjectives 133

prepositions, not adverbs, with respect to one or both of constructions (a) and (b)
above, but which NEVER take NP complements. We list in [12] a number of those that
occur both as dependents of nouns and as complement to be, as illustrated in [13]:
these are words which should very clearly be reassigned to the preposition category.

[12] abroad downstairs here outdoors overboard overseas there

ii ahead because instead

[13] DEPENDENT OF NOUN

a. Yo u can use [the offi ce downstairs].

ii a. [Water instead of wine] won 't do!

COMPLEMENT OF BE

b. The spare chairs are downstairs.

b. This is instead of your usual lunch.

The words in [12i] normally occur without complements; four are compounds

incorporating a core preposition (down, out, over) as the first element.

Those in [12ii] take complements with the form of PPs: ahead of us, because gJ

the weather, etc.

3 Further category contrasts

The differences between prepositions and nouns are too obvious to merit
further discussion, but it may be helpful to compare the syntactic properties of
prepositions with those of adjectives and verbs - not so much with a view to redraw­
ing the boundaries between these categories, but simply to clarify the differences
between them.

3.1 Prepositions vs adjectives

We deal here with the main features that distinguish between the prepo­
sition and adjective categories in the great mass of clear cases, setting aside a very
small number of highly exceptional words whose status as adjective or preposition
is problematic and controversial.

(a) NP complements

Prototypical members of the preposition class license NP complements. Adjectives
do not.

(b) Inflection and gradability

Prototypical adjectives inflect for grade (with plain, comparative and superlative
forms such as big, bigger, biggest) or else have comparatives and superlatives
marked by the modifiers more and most (e.g. useful, more useful, most useful). More
generally, they are gradable, accepting a range of degree modifiers including, most
disti nctively, very and too ("excessively") - cf. Ch. 6, § 1.3.
Prepositions, by contrast, are normally non-gradable. There are, however, some
PPs with specialised meanings that do permit certain kinds of grading - PPs such as
those in [14]: