A, an and the: make the noun clear

Introduce one countable thing

Use a or an when introducing one countable thing that the listener does not yet need to identify. “I bought a notebook” tells us the kind of object and that there is one. It does not assume the listener knows which notebook. Singular countable nouns usually need an article or another determiner: a notebook, my notebook, this notebook.

Choose a or an by the first sound of the next word, not just its first written letter. Use “a university” because university begins with a /y/ sound, and “an hour” because the h is silent. If an adjective comes first, listen to the adjective: “a bag” but “an old bag”.

• a book · a useful book
• an apple · an empty bottle
• She is an engineer. He is a teacher.

Use the when the listener can identify it

Once you have introduced an object, you can often refer to it with the: “I bought a notebook. The notebook has a blue cover.” The second sentence refers to the notebook already mentioned. Starting with “the notebook” would imply that the listener can identify it from some earlier context.

An object can also be identifiable from the situation: “Please close the door” is natural when both people know which door is meant. The does not mean that only one such object exists in the world. It means the relevant object or group is identifiable in this context.

• A dog came into the garden. The dog looked hungry.
• Could you pass me the salt? It is beside your plate.

Talk about things in general

Use a plural countable noun without an article for a general statement: “Books can be expensive.” Use an uncountable noun without an article when speaking generally: “Water is essential.” Compare “The books on this shelf are expensive”, which identifies a particular group.

Do not put a or an directly before an uncountable noun such as advice or information. Say “some advice”, “a piece of advice” or “some information”. To count it, choose a suitable unit: “a bottle of water”. Everyday English has exceptions and special uses, but this distinction is a useful starting point.

Check the meaning before filling a gap

More than one article may be grammatically possible without context. “I need an umbrella” asks for any suitable umbrella. “I need the umbrella” points to a particular one. Ask two questions: Is the noun countable and singular? Can the listener already identify the thing I mean? The answer helps you choose more reliably than memorising the noun alone.

Practise and check your reasoning

Say or write each answer before opening the explanation. If you make a mistake, identify which part of the rule changes your answer.

1. Introduce any one suitable object: I need ___ umbrella.

   Show answer and explanation

   an

   Umbrella is singular and countable, is not yet identified, and begins with a vowel sound.

2. Choose a or an: We waited for ___ hour.

   Show answer and explanation

   an

   Hour begins with a vowel sound because the h is silent.

3. Choose a or an: This is ___ useful example.

   Show answer and explanation

   a

   Useful starts with a consonant /y/ sound, despite its initial letter u.

4. Complete: I saw a cat near our gate. ___ cat was sleeping.

   Show answer and explanation

   The

   The second sentence refers to the cat introduced in the first.

5. Correct this sentence: She gave me an advice.

   Show answer and explanation

   She gave me some advice. / She gave me a piece of advice.

   Advice is uncountable in this use. It cannot directly take an.

Use it in your own words

Write a two-sentence description of an object near you. Introduce it with a or an, then refer to the same object with the. Next, write one general statement about books, music or water and explain why it does or does not need an article.

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