a, an and plurals

One or many?

• Use a / an to introduce one countable thing: a book, an apple. Other words can come before a singular noun too: my book, this apple, the bag.
• Use a plural for more than one in these examples: two books, three apples. A plural does not always end in -s: two children.
• Outcome: choose an article by sound and a noun form that fits the meaning. Start with this, that, these and those. Starting check: is my bag missing a? No — my already introduces the bag.

One apple is a snack. Ten apples are a plan.

a and an

• a before a consonant sound: a car, a dog.
• an before a vowel sound: an egg, an hour (h is silent). Use a university: its first sound is /j/, like the start of yes. Check the next sound, not the first letter.
• Use them only with singular countable nouns.

Plurals: -s, -es, -ies

• Most nouns: add -s → book → books.
• Common -es plurals include bus → buses, dish → dishes, box → boxes. Many words ending in -ch do this too, such as watch → watches; spelling rules have exceptions, such as stomach → stomachs.
• Consonant + y: change y to i, add -es → baby → babies.

Irregular plurals (learn these!)

• man → men, woman → women, child → children.
• foot → feet, tooth → teeth, person → people.
• These common irregular forms need practice. Some nouns also have other plural uses: persons occurs in formal notices; people is the ordinary plural in three people. Do not add -s mechanically to every noun.

Common mistakes

• To introduce one dog here, say I have a dog, not I have dog. But my dog, this dog and the dog can also be correct in other sentences; do not add a before them.
• For two of these objects, use two books, not two book. The number one takes the singular; some plural forms change differently, as in two children.
• ❌ a hour → ✓ an hour — the h is silent. Listen to the sound, not the letter.

Usage guidance checked 2026-10-20: Cambridge, a/an and the. Local source checks; independent language, answer and learner review pending.