Prepositions are words that tell (specify) location, both in time and place.  Specifically, these words can describe something at one place, an object’s location in relation to other objects (above and below, being closer or farther). Prepositions also describe an object in time, at both one time and over an extended amount of time. 

Examples

Place

My pen is on the pie.

My iPod is in the soup.

My homework is under the dog.

Time

I have class at 7:00. 

I didn’t find my phone until midnight.

I haven’t seen my wallet since last weekend.

What’s an "Object of a Preposition"?

An object of a preposition is a noun, pronoun, or gerund noun that pairs up with a preposition. The examples already looked at all have object of prepositions.  Have you ever wondered what a prepositional phrase is? A prepositional phrase is formed by adding a preposition and an object of preposition. 

Examples

The toothpaste is near the sink.

I keep in shape by running.

My computer charger is plugged into the wall. 

(Here into is the preposition; the wall is the object of preposition.  Together they form a prepositional phrase.)

Common Errors

Unneeded Additional Prepositions

Often people add prepositions when they do not need to

Meet up with SHOULD BE meet / Where are they at? SHOULD BE where are they?

Dates and Times

Use “in” or “for” with general measurements and “on” or “at” for specific dates.

Mitch was at school in the morning. / The essay is due at 11:00 PM on the 8th.

Chart of Prepositions

about
above
according to
across
after
against
along
along with
among
apart from
around
as
as for
at
because of
before
behind
below
beneath
beside
between
beyond
but*
by
by means of

concerning
despite
down
during
except
except for
excepting
for
from
in
in addition to
in back of
in case of
in front of
in place of
inside
in spite of
instead of
into
like
near
next
of
off
on

onto
on top of
out
out of
outside
over
past
regarding
round
since
through
throughout
till
to
toward
under
underneath
unlike
until
up
upon
up to
with
within
without