Using "the" or "a" for an item already mentioned

Question

I was reading a topic article in a English grammar book.

In an explanation, the following guideline was mentioned:

Use the to refer something that has already been mentioned.

While I was doing an exercise, I faced the following sentence.

3. Our teacher gave us ______ test today. It was ______ really hard test.

There were questions on there which I didn't even understand. But based on the explanation above, the answer in the first sentence should be a, and the answer in the second sentence should be the.

But when I saw the answer, there was a in first sentence and a in the second sentence also.

How is this possible? Based on the explanation, the answer in the second sentence should be the! Please explain.

Answer 1

It's a trick question, because the phrasing is altered in the second sentence.

Look at it this way: I say to you:

• I like you. You are a smart person.

In the above, I already mentioned "you" in the first sentence, but I didn't mention "smart person" in the first one. Not only that, but if I had said "You are the smart person," that would mean that I think there is no other smart person except you.

Now, back to your example. "Test" was already mentioned, but "really hard test " wasn't:

In the second sentence, the subject is "it", a pronoun, which stands in for "the test already mentioned". "It" is then equated to "really hard test", which hadn't been already mentioned.

So, you see, the use of a pronoun (namely "it") changes everything.

This is a subtle distinction, so don't be worried because the question (that you mentioned) fooled you. A question (another one, not yet mentioned) as subtle as that one (the one you mentioned) might fool any English learner (you or another one).

But IF the second sentence had actually used "test" as the subject, "the" would have been appropriate, just as you would expect based on the explanation you cited.

• The test was a really hard test.

But that repeats "test" too many times (three, counting once in the first sentence). That's why the example shortened to:

• It was a really hard test.

one could also say:

• The test was really hard.

or:

• The test was a really hard one.

Each of the above three ways uses "test" twice in two sentences, which, strictly speaking, is not necessary. The below is shorter still, and is how an AmE speaker would probably say the second sentence:

• It was really hard.

(In the above, by eliminating "test" altogether, the native speaker completely avoids the question of a vs. the !)

Keep studying and asking. And I suggest you try posting questions on English Language Learners Stack Exchange, and reviewing others' questions there as well.

Answer 2

1 Tests such as this one over the usage of articles are usually useless. This is because a native speaker can think of a context in which either a or the could be correct in either blank. Thus depending on the context, what the speaker assumes about the listener, and what the speaker wants to say, the following could all be correct in your example:

a and a
a and the
the and a
the and the

2 The guideline is a poor one and it does not match reality. Go read any random article in the newspaper or a magazine and look at the articles used. The definite article will be used in about 60 to 70‰ of first mentions.

On this topic in general, you may this answer of mine informative and even useful.

In short, if the speaker assumes his listener can identify which test he is talking about, he can (but is not required) to use the. Otherwise, he may use a.