Cardinal numbers in English

The numbers Cardinal (cardinal numbers) are employed to designate quantities.

Number	Cardinal number in English	Number	Cardinal number in English
0	zero	80	eighty
1	one	81	eighty-one
2	two	82	eighty-two
3	three	90	ninety
4	four	93	ninety
5	five	94	ninety-four
6	six	95	ninety-five
7	seven	100	a / one hundred
8	eight	113	a / one hundred (and) thirteen
9	nine	187	a / one hundred (and) eighty-seven
10	ten	200	two hundred
11	eleven	235	two hundred (and) thirty-five
12	twelve	287	two hundred (and) eighty-seven
13	thirteen	300	three hundred
14	fourteen	350	three hundred (and) fifty
15	fifteen	390	three hundred (and) ninety
16	sixteen	400	four hundred
17	seventeen	403	four hundred (and) tree
18	eighteen	462	four hundred (and) sixty-two
19	nineteen	500	five hundred
20	twenty	515	five hundred (and) fifteen
21	twenty-one	567	five hundred (and) sixty-seven
26	twenty-six	589	five hundred (and) eighty-nine
30	thirty	600	six hundred
33	thirty-three	661	six hundred (and) sixty-one
35	thirty-five	699	six hundred (and) ninety-nine
40	forty	700	seven hundred
42	forty-two	770	seven hundred (and) seventy
47	forty-seven	773	seven hundred (and) seventy-three
50	fifty	800	eight hundred
54	fifty-four	820	eight hundred (and) twenty
59	fifty-nine	834	eight hundred (and) thirty-four
60	sixty	900	nine hundred
68	sixty-eight	935	nine hundred (and) thirty-five
61	sixty-one	988	nine hundred (and) eighty-eight
70	seventy	1,000	a / one thousand
76	seventy-six	1.003	a / one thousand (and) three
78	seventy-eight	2,000	two thousand

Other cardinal numerals

• 1,000,000: a million or one million
• 1,000,000,000: a billion or one billion
• 1,000,000,000,000: a trillion or one trillion

Particularities of cardinal numbers in English

When to use “a / an” or “one”

When specifying unit quantity before hundreds or thousands, it is possible to use both “a / an” and “one”.

Examples :

• I’ve said the same thing a hundred times and they still didn’t get it . (I’ve said the same thing a hundred times and they still don’t understand.)
• I’ve said the same thing one hundred times and they still didn’t get it . (I’ve said the same thing a hundred times and they still don’t understand.)

Note that, in the above sentence, there was no change in meaning regardless of the use of “one” and “a”.

Hundred is the word used to indicate hundreds. What defines the number of hundreds is the word used before it. In English “a” is an indefinite article and can mean “one” or “one”.

The same is true of the word “thousand”. Watch the excerpt from the song A thousand miles , by Christina Perri:

I have died everyday, waiting for you
Darling, don’t be afraid, I have loved you for a thousand years
I’ll love you for a thousand more

IMPORTANT : Before hundred and thousand is used to either one , but when the following word is a noun, it should always be inflected in the plural.

Note that in the music piece reproduced above, the word years is a noun and is inflected in the plural. In the last sentence, the word more is not a noun, but a pronoun.

Use of “and” between numerals

In English, the use of the word and (e) when writing the numerals in full is optional.

Examples:

• 9,852: nine thousand, eight hundred fifty-two or nine thousand and eight hundred and fifty-two.
• 21,720: twenty-one thousand, seven hundred twenty or twenty-one thousand and seven hundred and twenty
• 456: four hundred fifty-six or four hundred fifty-six

IMPORTANT : the word “and” is not used between ten and one unit. The numeral 38, for example, is written thirty-eight .

When to use “.” or”,”

In English, as a general rule, it can be said that the use of a semicolon is the opposite of that used in the Portuguese language. That is, when the comma is used in Portuguese, the period is used in English and vice versa. Let’s look at some cases.

Examples :

• There are 1,000 books on that shelf . (There are 1,000 books on that shelf.)
• There was an increase of 1.5% in the prices . (There was a 1.5% increase in prices.)

“-Teen” and “-ty” pronunciation

The suffix – teen is used from numeral 13 to 17:

• 13: thirteen
• 14: fourteen
• 15: fifteen
• 16: sixteen
• 17: seventeen

The suffix “- ty ” is used in the families of numerals 50, 60, 70, 80 and 90.

• 50: fifty
• 60: sixty
• 70: seventy
• 80: eighty
• 90: ninety

Here’s how to pronounce each of the suffixes:

• – ty / tí /
• – teen / tíin /

Phone numbers

Telephone numbers are usually said one by one. However, there are two particularities:

• Zero is usually read as “oh” / or /.
• When a number is repeated consecutively, it is common to use the word double before the numeral.

Examples :

• 2401-65 99: two four oh one, sixty-five, double nine
• 3321-77 30: double three two one, double seven, three oh