The indefinite articles

[evertgoran]

”I bought a book yesterday.”

”A man knocked on my door yesterday.”

I have been taught that the rules of ”a” and ”an” are to introduce something to the reader or listener, or to refer to any non-particular member of a group.

How can I distguish between when the indefinite articles are introducing a noun and when they are refering to any member of a group? They seem to do both at the same time but I’m not sure.

 

[Rover_KE]

Have you found that the usage of articles in English differs from their Swedish use?

 

[evertgoran]

How do you know that I’m Swedish? And also, yes they differ.

 

[Rover_KE]

I clicked on your Member Info right there on the left.

 

[evertgoran]

I see! Nice feature!

 

[Rover_KE]

See if this article answers your question.

 

[evertgoran]

Yes, I have read this one as well and this is where my question stems from. On the British counsel website they explain ”a” as doing two things (introducing and to show that it is one member or a group) but is ”a” doing both at once? That’s what I’m unsure about.

 

[teechar]

I have been taught that [STRIKE]the rules of[/STRIKE] ”a” and ”an” are used to introduce something to the reader or listener, or to refer to any non-particular member of a group.
How can I distinguish between when the indefinite articles are introducing a noun and when they are referring to any member of a group? They seem to do both at the same time but I’m not sure.

I'm not sure how useful the above explanation (or "rule") is. I prefer the straightforward grammatical method:
If you have a singular countable noun, and if it's non-specific, then it needs a determiner* (for example "a" or "an").

For example, let's take your second sentence above.

Man knocked on door yesterday.

We have two nouns in that sentence:

1- man: It's countable, singular and non-specific, so it needs an appropriate determiner.
2- door: It's countable, singular and non-specific, so it needs an appropriate determiner.

An appropriate determiner can be:
- An article (a/an)
- A possessive adjective (my, their, ... etc.)
- A possessive noun (the union's, Honda's, Jane's, ... etc.)
- A demonstrative (this, these, that, those)

Try, as an exercise, some possibilities for that sentence and post below.

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”I bought a book yesterday.”
”A man knocked on my door yesterday.”

In those sentences, the "book" and the "man" are being introduced to the reader. In other words, the author/speaker can then go on and say more about that book or that man.

However, consider the following sentences:

- A house in London would cost you a lot of money these days.
- An elephant can eat up to 300 kg of food per day.

Those are examples of referring to a non-specific member of a group. We are not talking about one house or one elephant.

 

[evertgoran]

I think I understand. Is it fair to say that both ”a” and ”an” refers to a particular thing that has not yeet been mentioned (isn’t known to the reader or listener) when not used as in your last examples:


- A house in London would cost you a lot of money these days.

- An elephant can eat up to 300 kg of food per day.

?

 

[teechar]

I'm not sure I understand your question, but if you're asking about the first case of the "rule" you mentioned in post #1, then yes.

She bought a dress, two skirts and a pair of jeans yesterday. The dress cost the most.

 

[evertgoran]

Sorry, I’ll try to explain a bit more in detail what I meant.

”I bought a shirt yesterday.”

Here the speaker is talking about a specific shirt, but it isn’t yet known to the listener, and therefore ”a” is used?

But, if the speaker were to say ”I’d like to buy a shirt” then the speaker is referring to one, non-specific, shirt out of all the shirts in the world?

Is this correct?

 

[teechar]

Here the speaker is talking about a specific shirt, but it isn’t yet known to the listener, and therefore ”a” is used.

But, if the speaker were to say ”I’d like to buy a shirt” then the speaker is referring to one, non-specific, shirt out of all the shirts in the world.

Is this correct?

Yes.