Commas rule 1

Commas with Numbers

Use commas to separate off the thousands and millions in compound numbers.

Example: 3,460,759

Don’t use commas in decimals.

Example: $3.49

Use a comma before the year if the date is given as follows: month, day, year.

Example: April 16, 2003

Don’t use a comma if only two elements of the date are given (e.g. month and year).

Example: I was born in May 1972.

Commas with Salutations

Use a comma if the sentence starts with an address to someone.

Example: Greg, can I talk to you for a second?

Use a comma with salutations in private letters.

Example: Dear Francis,

Don’t use a comma with salutations in business letters. Use a colon in American English and no punctuation mark in British English.

Example:
 BE – Dear Mr Jefferson
 AE – Dear Mr. Jefferson:

After the greeting, the comma is optional.

Example:
 Sincerely,
 Sincerely