My number is 0044 20 7869 4452. My number is 0044 20 7869 4452.
| 0 | zero / 'o' | 19 | nineteen |
| 1 | one | 20 | twenty |
| 2 | two | 21 | twenty-one |
| 3 | three | 22 | twenty-two |
| 4 | four | 23 | twenty-three |
| 5 | five | 24 | twenty-four |
| 6 | six | 25 | twenty-five |
| 7 | seven | 26 | twenty-six |
| 8 | eight | 27 | twenty-seven |
| 9 | nine | 28 | twenty-eight |
| 10 | ten | 29 | twenty-nine |
| 11 | eleven | 30 | thirty |
| 12 | twelve | 40 | forty |
| 13 | thirteen | 50 | fifty |
| 14 | fourteen | 60 | sixty |
| 15 | fifteen | 70 | seventy |
| 16 | sixteen | 80 | eighty |
| 17 | seventeen | 90 | ninety |
| 18 | eighteen | 100 | one hundred |
1. We say each digit of a phone number separately: 01622 613579
My number is zero one six two two six one three five seven nine.
My number is sixty-one thirty-five seventy-nine. 
2. We can say 'zero' or 'o' 03 21 13 75 23 =
'o' three two one one three seven five two three
or
zero three two one one three seven five two three
3. 33 = three three or double three
Other numbers
236 = two hundred and thirty-six
4,567 = four thousand, five hundred and sixty-seven
Sometimes we can say the digits separately. For example:
Flight no. BA5786 = BA five seven eight six
Room no. 236 = Room no. two hundred and thirty-six or two three six
2610 Castle Avenue = two thousand, six hundred and ten or two six one 'o' Castle Avenue
=====Time=====
| We write | or | We say | or |
| 01:00 | 1:00 a.m. [or am] | one (a.m.) | one o'clock (in the morning) |
| 02:00 | 2:00 a.m. | two (a.m.) | two o'clock (in the morning) |
| 03:00 | 3:00 a.m. | three (a.m.) | three o'clock (in the morning) |
| 12:00 |
| twelve (noon/midday) |
|
| 13:00 | 1:00 p.m. [or pm] | one (p.m.) | one o'clock (in the afternoon) |
| 14:00 | 2:00 p.m. | two (p.m.) | two o'clock (in the morning) |
| 15:00 | 3:00 p.m. | three (p.m.) | three o'clock (in the afternoon) |
| 16:00 | 4:00 p.m. | four (p.m.) | four o'clock (in the afternoon) |
| 17:00 | 5:00 p.m. | five (p.m.) | five o'clock (in the afternoon/evening) |
| 18:00 | 6:00 p.m. | six (p.m.) | six o'clock (in the evening) |
| 19:00 | 7:00 p.m. | seven (p.m.) | seven o'clock (in the evening) |
| 20:00 | 8:00 p.m. | eight (p.m.) | eight o'clock (in the evening/at night) |
| 21:00 | 9:00 p.m. | nine (p.m.) | nine o'clock (in the evening/at night) |
| 22:00 | 10:00 p.m. | ten (p.m.) | ten o'clock (in the evening/at night) |
| 23:00 | 11:00 p.m. | eleven p.m. | eleven o'clock (in the evening/at night) |
| 00:00 |
| twelve midnight | twelve o'clock (at night) |
| We write | or | We say | or |
| 12:05 | 12:05 a.m./p.m. | twelve 'o' five (a.m./p.m.) | five past twelve (in the morning/afternoon) |
| 12:10 | 12:10 a.m./p.m. | twelve ten (a.m./p.m.) | ten past twelve (in the morning/afternoon) |
| 12:15 | 12:15 a.m./p.m. | twelve fifteen (a.m./p.m.) | quarter past twelve (in the morning/afternoon) |
| 12:20 | 12:20 a.m./p.m. | twelve twenty (a.m./p.m.) | twenty past twelve (in the morning/afternoon) |
| 12.25 | 12:25 a.m./p.m. | twelve twenty-five (a.m./p.m.) | twenty-five past twelve (in the morning/afternoon) |
| 12:30 | 12:30 a.m./p.m. | twelve thirty (a.m./p.m.) | half past twelve (in the morning/afternoon) |
| 12:35 | 12:35 a.m./p.m. | twelve thirty-five (a.m./p.m.) | twenty-five to one (in the morning/afternoon) |
| 12:40 | 12:40 a.m./p.m. | twelve forty (a.m./p.m.) | twenty to one (in the morning/afternoon) |
| 12:45 | 12:45 a.m./p.m. | twelve forty-five (a.m./p.m.) | quarter to one (in the morning/afternoon) |
| 12:50 | 12:50 a.m./p.m. | twelve fifty (a.m./p.m.) | ten to one (in the morning/afternoon) |
| 12:55 | 12:55 a.m./p.m. | twelve fifty-five (a.m./p.m.) | five to one (in the morning/afternoon) |
Note that
1. We only say 'o'clock' with whole hours when there are no minutes:
5 o'clock
half past 5 o'clock
twenty to 4 o'clock
2. We never say or write '13 o'clock' or 'half past seventeen' etc.
When talking about timetables or schedules, we may say:
eighteen hundred - 18:00 eighteen 'o' five - 18:05
This is also used by military personnel who say:
eighteen hundred hours - 18:00 'o' eight hundred hours - 08:00
All these expressions are very rare in everyday conversation.
"What time is it?" "It's five o'clock."
"It's five past twelve."
"What's your number?" "My office number is 0151 456778 and my mobile is 07719 345221."
"And your address?" "15 Church Street, Liverpool, L11DA."
"My flight number is EZY3456. It lands at 12:05. We can have lunch before the meeting at three."
"Here are your keys. You have room numbers 345 and 346 on the third floor. Enjoy your stay."
"We have fifty people in our Tokyo office and about a hundred in Europe."