eng5-W2· Welcome!· ~12 min

Numbers 1–100

Counting, the tens, and saying how old you are.

English numbers are learnt in two steps. First 1 to 20: one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty. Then the tens: twenty, thirty, forty, fifty, sixty, seventy, eighty, ninety, one hundred. Everything between is built by joining a ten and a unit with a hyphen: twenty-one, thirty-five, forty-two, ninety-nine. Three spellings catch everybody out. 'Forty' has NO u, although 'four' and 'fourteen' do. 'Fifteen' and 'fifty' are not spelled with 'five'. And the -teen numbers are easy to confuse with the -ty numbers when you hear them: thirteen and thirty, fifteen and fifty, eighteen and eighty. Numbers are also how you answer one of the first questions you will be asked: 'How old are you?' — 'I'm 12.' Notice that English says 'I am twelve', not 'I have twelve years'.

Key terms

unit — A number from one to nine.

ten — One of twenty, thirty, forty, fifty, sixty, seventy, eighty, ninety.

hyphen — The short line that joins a ten to a unit: twenty-one.

-teen — The ending of the numbers 13 to 19: thirteen, fourteen … nineteen.

-ty — The ending of the tens: thirty, forty, fifty … ninety.

How old are you? — The question about age. It is answered with be: 'I'm 12.'

One to twenty

Number	Word	Number	Word
1	one	11	eleven
2	two	12	twelve
3	three	13	thirteen
4	four	14	fourteen
5	five	15	fifteen
6	six	16	sixteen
7	seven	17	seventeen
8	eight	18	eighteen
9	nine	19	nineteen
10	ten	20	twenty

From 13 the numbers end in -teen.

The tens, and building the numbers between

Number	Word	Example between
20	twenty	twenty-one, twenty-eight
30	thirty	thirty-five
40	forty (no u!)	forty-two
50	fifty	fifty-six
60	sixty	sixty-three
70	seventy	seventy-nine
80	eighty	eighty-four
90	ninety	ninety-nine
100	one hundred	—

A ten and a unit are always joined with a hyphen.

The three spellings to watch

Wrong	Right	Why
fourty	forty	the u of four is dropped
fivteen	fifteen	five becomes fif-
fivty	fifty	five becomes fif-
twentyone	twenty-one	a hyphen joins the two parts
nineteen for 90	ninety	-teen is 19, -ty is 90

These four are where nearly every mistake happens.

✎Building a number over twenty

1The number: 47
2Step 1: take the ten: 40 → forty (no u)
3Step 2: take the unit: 7 → seven
4Step 3: join them with a hyphen: forty-seven

✎Asking and answering about age

1The question: 'How old are you?'
2Step 1: use the verb be, not have: 'I am' / 'I'm'
3Step 2: add the number: 'I'm 12.'
4Step 3: ask back: 'How old are you?' — 'I'm 11.'

🚫Common mistake

'Fourty' is not an English word. 40 is FORTY, with no u — even though 4 is four and 14 is fourteen.

🚫Common mistake

Do not say 'I have twelve years.' English uses the verb be for age: 'I'm twelve.'

⚠️Caution

Listen to the ending: thirteen (13) and thirty (30) differ only in -teen and -ty. The same goes for fifteen/fifty and eighteen/eighty.

💡Note

A ten and a unit are joined by a hyphen: twenty-one, not twenty one and not twentyone.

💡Note

The Welcome unit asks you to count by twos with a partner: two, four, six, eight … It is a good way to fix the tens in your memory.

Rules

1Learn 1–20 as separate words, then the tens: twenty, thirty, forty, fifty, sixty, seventy, eighty, ninety.
2Join a ten and a unit with a hyphen: twenty-one, forty-five, ninety-nine.
3'Forty' has no u — even though 'four' and 'fourteen' do.
4'Fifteen' and 'fifty' drop the -ve of 'five'.
5-teen numbers (13–19) and -ty numbers (30–90) sound similar. Listen to the ending.
6Age is said with the verb be: 'I'm 12.' — not 'I have 12 years.'

Practice

10 easy · 10 medium · 10 hard

Up to 10 random questions per test

Easy Medium Hard Mixed