It’s somewhat ironic that two of the most common words in the language – the and a – are also the hardest to explain. It’s not that we lack data – maybe there’s too much data and it’s impossible to see the wood for the trees. At any rate, the definite and indefinite article must win the prize for having the most nonsense written about them in coursebooks and student grammars.
Here’s how one upper intermediate coursebook (name withheld out of courtesy) explains the indefinite article:
“We use the indefinite article a when we are talking about a single countable noun in a general non-specific way or when we introduce it for the first time: There was a car outside the bank.”
This explanation conflates and confuses a number of facts. Starting with the second rule first, this is easily disproved in sentences like: “We decided to eat at a restaurant. The waiter showed us to a table….” The waiter is first mention, yet takes the definite article. And, while we’re at it, what about second mention? According to the coursebook rules, the second mention of a noun is definite, and takes the. Well, what about this: “The waiter showed us to a table. It was a small table, so we asked for another…” Second mention but indefinite article!
But more on the discourse function of articles in another post.
Let’s go back to the first rule: “We use the indefinite article a when we are talking about a single countable noun in a general non-specific way…”
Wrong. The indefinite article can be used for general AND specific reference:
A tiger will bite if provoked = any tiger (generic reference, and indefinite)
A tiger bit me when I provoked it = specific tiger, although indefinite.
Is there a doctor on board? = any doctor, one of the class of doctors (generic, indefinite)
I sat next to a doctor on board. = a specific doctor (specific, indefinite)
(The ambiguity inherent in the indefinite article is exploited in jokes like: In (such-and-such-a-city) a person gets mugged every ten minutes. And he’s getting mighty sick of it!)
The definite article – the – can also be used for both generic and specific reference, but in either case, there is an assumption of shared knowledge:
The tiger hunts by night and sleeps by day = generic, definite
The tiger bit me! = specific, definite.
In other words, for both a and the, there are two parameters that intersect: specificity, and definiteness. And they are not the same thing.
Nouns in the plural can also have generic or specific reference, but only when indefinite – i.e. with zero article:
Tigers hunt by night and sleep by day = generic, indefinite
Tigers bit me = specific, indefinite
The tigers bit me = specific (NEVER generic), definite
In other words, you can’t say the tigers to mean the class of tigers – a common learner error: *I like the cats. *The bananas are good for you, etc.
Now, why am I telling you all this? Because I stupidly didn’t mention this in the A-Z. I completely omitted to point out that the generic-specific dimension operates across the definite-indefinite one.
Next time round, I’ll include the following chart (where the examples with asterisks are non standard, where the sign Ø stands for the zero article, and where I’ve included non-count nouns as well):
|definite||She plays the violin.
The whale is a mammal.
(*The whales are mammals.)
(*I like most types of the music.)
|She played the violin I gave her.
Can you see the whale over there?
The violins are too loud.
I didn’t like the music in the film.
|indefinite||Let’s give her a violin.
A whale cannot breathe underwater.
Ø Whales cannot breathe underwater.
I like most types of Ø music.
|I saw a nice violin in town yesterday.
Captain Ahab was killed by a whale.
There are Ø whales in the Mediterranean.
Listen: I can hear Ø music!
Does that make any sense?