Dear students, many of you speak quite good English. Though you often come across some grammar issues which you are not sure about. That is why I decided to bring up explanations of a few basic phenomena related to grammar. My first “grammatical window” is dedicated to prepositions.
Prepositions are a closed word class. They express a relation in time between two events or relation in space between two (or more) things or people.
(Carter R., McCarthy M., Cambridge Grammar of English, 2006)
The most often used prepositions are: in, at, on, to, with, by, during, for, about, of, from, after. Let’s start with three basic ones.
IN, AT, ON
The prepositions are used in connection with places.
When we want to express that something is INSIDE, we use the preposition “in”:
Study these examples: in a room, in a building, in a box
These objects have definite borders, it means that things are located within a part of the mentioned area. We use it with 3D objects as well as with 2D: in a garden, in a town/city, in a country.
We say “on” if something is not placed inside a particular area but on the borders of its tangible part, either on the top, bottom or its sides.
Look at the examples: on the ceiling, on the floor, on the wall, on your nose, on the door etc.
A very special place among the prepositions has “at”. It is used when the object is situated right at or near the particular point.
Examples: at the top of the page, at the end of the street, at the bus stop, at reception…
The prepositions IN, ON, AT are also used with the time. There is no clue which helps you identify, which preposition should be used. You just need to learn it by heart (memorize).