Numbers 0-20
English numbers are regular except for a cluster of irregular forms between eleven and fifteen. Those are the ones worth memorising deliberately.
Vocabulary
- zero
- 0
- one
- 1
- two
- 2
- three
- 3
- four
- 4
- five
- 5
- six
- 6
- seven
- 7
- eight
- 8
- nine
- 9
- ten
- 10
- fifteen
- 15
- twenty
- 20
Example Phrases
How old are you?
Asking someone's age
I'm twenty years old.
Giving your age
How much is it?
Asking a price
That's ten pounds.
Giving a price
Grammar note
"I am" for age, not "I have"
English uses be for age: I'm twenty, she's thirty. Speakers of French, Spanish, and Italian often say I have twenty years, which is a very recognisable error.
You can drop years old in casual speech — I'm twenty is complete on its own.
Cultural note
Thirteen or thirty?
The -teen and -ty pairs (thirteen/thirty, fourteen/forty) are a genuine listening difficulty. The difference is stress: THIRteen puts weight on the second syllable, THIRty on the first.
Asking someone to confirm — one-three or three-zero? — is completely normal, including among native speakers.