In English, numbers are used to count, label, measure, and talk about time, dates, prices, and quantities. You will use cardinal numbers for counting, ordinal numbers for order, and common number patterns for large values, decimals, and fractions. This module focuses on the forms you need to say, read, and write numbers naturally in everyday contexts.

Cardinal numbers answer “How many?” and are used for counting and quantities. English forms are built from basic numbers 0–19, tens like 20, 30, 40, and combinations like 21, 57, 99. For numbers 21–99 that are not exact tens, use a hyphen in writing: twenty-one, sixty-five. Use “and” only in specific styles, especially British usage for 101+ in some contexts.

Word/Phrase	Definition	Example
zero	Number 0	I have zero messages.
one	Number 1	One ticket, please.
two	Number 2	Two coffees, please.
ten	Number 10	It costs ten dollars.
eleven	Number 11	Eleven people came.
twenty	Number 20	We waited twenty minutes.
forty	Number 40	She is forty years old.
hundred	100	A hundred pages.
thousand	1,000	Two thousand residents.
million	1,000,000	A million views.

Ordinal numbers answer “Which one?” and show order, position, or sequence. Most ordinals add -th, but some are irregular: first, second, third. In writing, you often see 1st, 2nd, 3rd, 4th. Ordinals are common with dates, floors, rankings, and steps in instructions.

Word/Phrase	Definition	Example
first	Position 1	This is my first day.
second	Position 2	Take the second left.
third	Position 3	He finished third.
fourth	Position 4	The fourth chapter is short.
fifth	Position 5	It’s on the fifth floor.
21st	Ordinal for 21	My birthday is on the 21st.

For large numbers, English groups digits in threes: thousand, million, billion. In most English writing, use commas as separators: 1,000; 25,000; 3,500,000. When saying large numbers, you can break them into chunks: three million five hundred thousand. “A hundred” and “a thousand” are common in speech, but the exact number is used in formal contexts.

Rule	Example
Use thousand, million, billion for 10³, 10⁶, 10⁹	2,000,000 is two million.
Say numbers in grouped chunks	350,420 is three hundred fifty thousand four hundred twenty.
Use commas in standard number formatting	The population is 1,250,000.
Use a before hundred and thousand in casual speech	It’s a hundred miles away.

Fractions describe parts of a whole and are common in recipes, measurements, and everyday quantities. Use “a” for one when speaking: a half, a quarter. Pluralize the denominator when the numerator is greater than one: two thirds, three quarters. For mixed numbers, say the whole number then the fraction: two and a half.

Rule	Example
Use a for common fractions	I’ll have a half.
Use plural denominators for numerators over one	Two thirds of the class agreed.
Say mixed numbers with and	It’s two and a half hours.
Quarter is common for one fourth	Add a quarter cup of milk.

Decimals are used for prices, measurements, and precise values. Say the decimal point as “point,” then read digits individually: 3.14 is three point one four. For money, you often say the amount in dollars and cents: $2.50 is two dollars and fifty cents, or two fifty in informal speech. Leading zeros are spoken: 0.5 is zero point five.

Rule	Example
Say point for the decimal symbol	4.6 is four point six.
Read digits after the point one by one	7.03 is seven point zero three.
For prices, use dollars and cents or a short form	$3.75 is three dollars and seventy-five cents.
0️⃣ Say zero before the point when needed	0.8 is zero point eight.

To tell time in English, you can use a digital style with hours and minutes or a conversational style with past and to. For exact times, say the hour then the minutes: nine fifteen, six forty. Use o’clock for exact hours: five o’clock. Use a.m. for times from midnight to before noon, and p.m. for times from noon to before midnight.

Rule	Example
Say hour then minutes for most times	It’s 8:20. It’s eight twenty.
Use o’clock only for exact hours	It’s 3:00. It’s three o’clock.
Use a.m. for morning times	The meeting is at 9 a.m.
Use p.m. for afternoon and evening times	Dinner is at 7 p.m.

A common conversational way to tell time uses past for minutes after the hour and to for minutes before the next hour. Use quarter past for :15 and half past for :30. For :45, you often say quarter to the next hour. This style is frequent in British English and also understood widely in other varieties.

Rule	Example
Use past for minutes 1–30 after the hour	6:10 is ten past six.
Use to for minutes 31–59 before the next hour	6:50 is ten to seven.
Use quarter past for :15	2:15 is quarter past two.
Use half past for :30	9:30 is half past nine.
Use quarter to for :45	4:45 is quarter to five.

Time phrases locate events relative to now and help you schedule naturally. Use at for clock times, on for days and dates, and in for months, years, and longer periods. Use expressions like in the morning, at night, and on the weekend depending on variety. These patterns connect numbers to real-life time and make your speech sound natural and precise.

Rule	Example
Use at for clock times	The train leaves at 6:45.
Use on for days and dates	It’s on Monday. It’s on April 10.
Use in for months, years, and seasons	We met in 2022.
Use in the morning, in the afternoon, in the evening	I work in the morning.
Use at night	It’s quiet at night.

Use cardinal numbers for counting and quantities and ordinal numbers for order, floors, and dates. Build large numbers with thousand, million, and billion, and read them in chunks. Say fractions and decimals with consistent spoken patterns, especially point for decimals. For time, use hour-minute style or the past and to style, and combine times with at, on, and in to place events correctly.