Definition / Explanation
We use a and an with singular countable nouns when we mean one thing, but not a specific one. This is often the first time we mention something or when it is one example of a larger group. Use a before a consonant sound and an before a vowel sound. The choice depends on sound, not only on spelling.
Key Rules
- Use a before words that begin with a consonant sound: a book, a car.
- Use an before words that begin with a vowel sound: an apple, an engineer.
- Use a/an only with singular countable nouns.
- Do not use a/an with plural nouns or uncountable nouns.
- We often use a/an when we mention something for the first time.
Examples
- I have a dog.
- She is an artist.
- He needs a new phone.
- We saw an old house.
- There is a shop near the station.
Common Mistakes
- ❌ I have dog. -> ✅ I have a dog.
- ❌ She is a engineer. -> ✅ She is an engineer.
- ❌ There is an cars outside. -> ✅ There are cars outside.
Tips
- Listen for the sound, not only the letter: an hour but a university.