Articles — a, an, the

a, an, the — small words, big job

• Articles come before nouns. English uses them a lot — Chinese doesn't.
• a / an = one, not specific. the = a specific one we both know.
• Sometimes we use no article at all.

A cat came in. The cat now owns the sofa.

a / an — one, not specific

• Use before a singular countable noun: a book, an apple.
• a before a consonant sound; an before a vowel sound.
• Listen to the sound: an hour (h is silent), a university (it starts "yu-").

the — the specific one

• Use the when we both know which one: Close the door.
• For something mentioned again: I saw a cat. The cat was black.
• For unique things (the sun, the moon) and before superlatives (the best).

zero article — no word at all

• Plural / uncountable nouns in general: I like music. Cats are cute.
• Names of people, most countries, cities: Tom, China, Beijing.
• Fixed phrases: go to school / bed / work.

Common mistakes

• ❌ I want to be teacher. → ✓ I want to be a teacher. — jobs need a / an.
• ❌ I went to home. → ✓ I went home. — no to, no the before home.
• ❌ He plays the football. → ✓ He plays football — but: play the piano.