As I noted in this blog in December 2018, people learning English can sometimes get frustrated with prepositions. Please read that one again if you would like a short introduction to what prepositions are, and how they work grammatically. Let’s remind ourselves that despite their apparent lack of logic, prepositions are quite simple: they show the relationship of one thing to another, or the position an object is in.
The most common types of prepositions refer to time, place, and movement.
Consider this sentence: “I am at work.”
In the English sentence above, “at” explains the relationship between “I” (a noun) and “work” (another noun). In this example, it is a preposition of place.
Generally speaking, we use “at” like this when we want to say that something is located in a general area. When you are at work, you could be anywhere around that workplace – in your office, or in a meeting, or having lunch. All of these places are “at work”.
When you go home, and are now at home, you are not in one specific location. You could be in any of the rooms in your house, or in your back yard, or even on your roof. When you are at the door, you could be to the left of it, to the right of it, or right in front of it, on the inside of it, or on the outside of it. You could be eating your dinner at your table, and that means anywhere around the table.
However, if you decide to work remotely from home, you are not at work. Instead, you are working from home. You can only be at work when you are at home if you have a home office and your home really is your workplace.
If you arrange to meet your friends at the movies, then good luck finding them! The building housing a multiplex cinema can be quite big, and you haven’t specified where you will be – you could be outside the front doors, or in the foyer, about to buy popcorn, or next to one of the theatres. So, it’s better to pinpoint the exact location: “I’ll meet you at the Supermovie Multiplex by the box office.” With this kind of precision, everybody knows where you will be without further explanation.
“At” can be a preposition of movement. You could say: “She fired an arrow at the balloon.” More abstractly, you could say “We directed our marketing at young professionals.” Both of these suggest some kind of aim and movement in the direction of a target, although one refers to physical action and the other is more psychological.
“At” can also be a preposition of time. Many people go away at Christmas or at Easter. You might ask your friend: “What are you doing at New Year?” These are general periods, like the general location.
Note that the British say “at the weekend”, which fits the general period idea (some time across two days away from work). However, the Americans and Australians say “on the weekend.” It’s possible nobody knows why, but if you manage to find out, please tell me! This regional difference makes no sense.
Since English is a language of exceptions, here comes an exception: we also use “at” for an exact time. For example, “I’ll meet you at three o’clock”, or “It happened at midnight” or “The train leaves at 9:43”.
People employ “at” in other ways too, but these are the most common ones when it is working as a preposition. How else have you seen it used?