Prepositional phrases do not affect agreement
between the subject of the sentence and the verb.
Often a singular subject will be followed by
a prepositional phrase that contains a plural
word as the object of the preposition. Prepositional
phrases do not affect agreement between the
subject of the sentenceand the verb. We
can mentally "block out" the entire prepositional
phrase from the sentence while we decide whether
to use a singular or a plural verb.
For example, notice the plural words that are
objects of the prepositions of, in, and
at in the following sentence parts:
An examination of the records.
The spectator in the bleachers.
The worker at the controls.
When a verb follows such plural words, many of
us understandably (but mistakenly) make the verb
plural (as in "the worker at the controls are.
. ."). But the plural word (controls) that
follows the preposition is not the subject
of the verb that follows-the singular subject
that precedes the prepositional phrase is the
subject (the worker at the controls). Thus,
the sentence should read: "The worker at the controls
is. . .").