Purdue University North Central Writing Center Handout

                              Prepositions of Location:   AT,  IN,  ON

 

            Prepositions expressing spatial relations are of two kinds: prepositions of location and prepositions of direction.  Both kinds may be either positive or negative.  Prepositions of location appear with verbs describing states or conditions, especially BE; prepositions of direction appear with verbs of motion.  This handout deals with positive prepositions of location that you may be having difficulty with: at, on, and in.

 

            The handout is divided into three sections.  The first explains the spatial relationships which the three prepositions express.  The second and third contrast special uses of IN and ON, and IN and  AT, respectively.

 

DIMENSIONS AND PREPOSITIONS

Prepositions differ in how many dimensions in space they refer to.  We can group them, using concepts from geometry, into three classes: 1) point, 2) surface, 3) area or volume.

 

Here are brief descriptions of these three dimensions:

Point--Prepositions in this group indicate that the noun that follows them is treated as a point in relation to which another object is positioned.

Surface--Prepositions in this group indicate that an object’s position is defined with respect to a surface on which it rests.

Area/Volume--Prepositions in this group indicate that an object lies within the boundaries of an area or within the confines of a volume.

 

In light of these descriptions, at, on, and in can be classified as follows:

Point—at                     Surface—on                Area/volume—in

 

The meanings of the three prepositions can be illustrated with some sample sentences: 

1)     My car is at the house.  

2)     There is a new roof on the house.   

3)     The house is in Tippecanoe County.     

4)     There are five rooms in the house.  In the living room is a lovely fireplace.

 

In 1) the car is located in relation to the house, conceived of as a fixed point.

In 2) the house, specifically the ceiling, is treated as a two-dimensional surface upon which another object,       the roof, is placed. 

In 3) the house is located within a geographical area. 

In 4) the house becomes a three-dimensional structure which can be divided into smaller volumes---namely, rooms--and inside one of the rooms is an object, the fireplace.

 

AT calls for further comment.  Because it is the least specific of the prepositions in its spatial orientation, it has a great variety of uses.  Here are some of them:

6) location:            a)  Tom is waiting for his sister at the bank.

                             b)  Sue spent the whole afternoon at the fair.

7) destination:        a)  We arrived at the house at six.

                             b)  Sue spent the whole afternoon at the fair.

8) direction:            a)  The policeman leaped at the assailant to apprehend him.

                             b)  The dog jumped at my face and really scared me.

9) intersection: I’ll meet you at the corner of Fifth and Main.               

 

In 6a), the bank can be taken to be a point that defines Tom’s location, much as in 1) above.

In 6b) it makes less sense to think of a fair as a point since fairs are usually spread out over a fairly large area.  Probably at is used in this case because it is the least specific preposition; it defines Sue’s location with respect to the fair rather than some other place.

In 7a), at exhibits its cause/effect relationship with to, which cannot be used here: arrival at a place is the result of going to it.  For more on this, see the handout “Prepositions of Direction: To, (On)to, (In)to.”

The sentences in 8) show that, with certain verbs of motion, at may be used with the same meaning as its directional counterpart to, that is, of direction toward something.  Again, see the directional prepositions handout.

In 9) a special case of the general use of at is used since lines intersect at points physical objects resembling them like streets, paths, and so on do the same.

 

In the remainder of the handout, we will look at special problems that arise in choosing in and on or in and at

 

IN/ON

1.      Nouns denoting enclosed areas, such as field or window, take both on and in.  The preposition have their normal meanings with these nouns: on is used when the area is considered as a surface, in when it is presented as a two-dimensional area:

  1. Three players are practicing on the field. (surface)

Three cows are grazing in the field.  (area)

  1. The frost made patterns on the window (surface)

A face appeared in the window.   (area)

 

Observe that in implies that the field is enclosed, whereas on may or may not imply this since it implies only that the following noun denotes a surface and not necessarily an area:

The sheep are grazing in the pasture.  (area enclosed by a fence)

The cattle are grazing on the open range.  (not enclosed)

Three players are on the basketball court.  (enclosed by bleachers)

Three players are on the soccer field.  (not always enclosed)

 

2.      When the area has metaphorical instead of literal boundaries, as when field means “academic discipline,” in is used:

      She is a leading researcher in her field.

 

3.      Several common uses of in or on occur with street.  The first two follow the rules for using in and on.  The third is an idiom that must be learned as a unit.

a.      The children are playing in the street.

The street is understood to be an area enclosed by the sidewalks on either side.

b.      Our house is on Third Street.

Here on locates the house on either side of Third Street--it does not mean that the street is a surface on which the house sits.  Because the street is conceived of as a line next to which the house is situated, on functions much like at in its normal use in that it locates the house in relation to the street.  As such, it does not specify the exact address.  For that purpose, at is used, because the address is like a particular point on the line.  Compare: Our house is at 323 Third Street.

c.      He declared bankruptcy last week, and now he is out on the street.

Out on the street is an idiom meaning “poor” or “destitute.”

 


4.      In and on are also used with means of transportation:  in is used with car, and on with public or commercial means of transport:

in the car          on the bus on the plane      on the train      on the ship

Some speakers of English make a further distinction for public modes of transportation, using in when the carrier is stationary and on when it is in motion:

My wife stayed in/on the bus while I got out at the rest stop.

The passengers sat in/on the plane awaiting takeoff.

 

IN/AT

(These two prepositions are often confused.  The following rules cover most, although not all, cases.)

 

Geographic Locations

1.      Use in for place names:

small towns:      in Battleground                      countries:         in Russia

large cities:        in Cairo                                 continents:       in Africa

counties:           in Tippecanoe County             deserts:           in the Sahara

provinces:         in Quebec                               mountains:      in the Andes

states:               in California                            valleys:           in the Shenandoah Valley

 

2.      In is also used for common nouns denoting geographical locations:  in the desert, in the valley, in the mountains (but on the mountain when its sides are perceived as a surface).

 

3.      Use at for the North and South poles since these are thought of as points.

 

4.      Other uses of prepositions with geographic nouns conform to their ordinary uses.  Thus, we can say all of the following:

a.       They are spending the summer at the shore.

b.       We found a crab washed up on the shore.

c.       Their summer cottage is on the shore.

In 4a) the shore is meant as a point that fixes the family’s location during the current or upcoming summer.  In 4b) the shore is a surface on which the crab is lying.  In 4c) we have almost the same use as in 3b) in the previous section.

 

Buildings

1.      At is used with proper nouns denoting public buildings and public institutions: at Purdue, at the Pentagon, at the Capitol.

2.      With common nouns denoting public buildings, at is used when they are conceived of as institutions, and in is used when they are conceived of as three—dimensional physical structures.  In the sentences that follow, at is used because Tom is at a place for a purpose connected with its institutional function.

Tom is at the bank depositing his check.

Tom is at city hall applying for a zoning permit.

Tom is studying at the library.

3.      By contrast, in means physical presence inside of a three-dimensional structure, as in its ordinary spatial use.  It may thus further imply that a person is there for a purpose unrelated to the place’s primary function:

Tom is in the bank waiting for his father.

They are studying in the Sweet Shop.

 

Inside or Outside?

While the use of at with institutions and in with buildings holds quite generally, the basic meanings of at and in can also be used with common nouns denoting institutions as readily as they can with other nouns. 

In has its ordinary meaning of  “inside,” but at may mean either “inside” or “outside,” depending on two things: 1) where the speaker is in relation to the place being talked about; 2) whether the person spoken about is there for purpose of the institution or not.

 

When the speaker is physically present near the building, in is used, whether or not the person spoken about is there for the purpose of the institution.

Present for purpose of the institution:

Tom is studying in the library.

Jane is in the supermarket buying groceries for the party.

Not present for the purpose of the institution:

Tom is studying in the Sweet Shop.

Tom is waiting for his father in the bank.

 

When the speaker is not physically near the building, or, more exactly, when the speaker’s location is defined by referring to some other building, even if it is close by, at is used.  When the person spoken about is not in a place for its institutional purpose, at may mean either inside or outside.

Tom is waiting for his sister at the bank.

 

When the person spoken about is in a place for its institutional purpose, at normally means that she is inside.  The preferred interpretation would be the same if the person’s purpose were not specified: that is, she is inside for the institutional purpose.

Terry is at the library studying.  (in the library)

Terry is at the bank depositing her check.  (inside the bank)

Terry is at the grocery store.  (inside the store, shopping or working)

 

Special Uses

1.      With nouns denoting places of temporary confinement, in instead of at expresses the primary purpose of being in an institution.  This is a natural extension of the ordinary spatial meaning of on.  In this case, at expresses a secondary purpose.  Generally, in implies an extended stay, while at means a brief visit:

  1. Jane is in the hospital recovering from surgery.

      Tom is visiting Jane at the hospital.

  1. George is in the jail/prison because he could not post bail.

Tom is in the county jail visiting George.

 

2.      The idioms in school and at school have very different meanings.

“He is in school” means he is currently attending school.

“He is at school” means:

  1. that the person referred to is physically present in the building (as in the case of an elementary or secondary school) or on the campus (as in the case of a college or university) at the time the sentence is uttered or written;
  2. that the speaker/writer is not herself/himself at school—that is, the same school—when the sentence is uttered or written.  Compare this rule to the one given for at in the preceding section.

 

These are American English idioms.  Their meanings are reversed in British English; if you learned the latter, be careful to keep this difference in mind.