Articles: sound first, then shared context

Use the pattern in context

Choose a or an from the next spoken sound: a university, an hour, a useful tool, an old tool. Then check reference. I bought a lamp introduces a lamp; The lamp is blue refers to that identifiable lamp. General plural and uncountable statements often need no article: Books can help; Water is useful.

Examples to compare

• Introduce: I need a ticket.
• Identify: Is this the ticket you booked?
• General: I enjoy music.

Limits and useful distinctions

The rule is about sounds, not vowel letters. The is also more than a second-mention marker: a first mention can be identifiable, as in Close the door when one door is obvious. Names, meals and institutional expressions have additional patterns. Use the lesson and contextual questions to build beyond this starting contrast.

Check your understanding

Why is it an hour rather than a hour?

Try a new example with the same purpose. Check that your version keeps the intended meaning and grammatical pattern.