Punctuation provides pause and creates style
Let’s look at some uses of the comma that cannot be ignored!
Use a comma to separate a state from a city.
Use a comma in the month-day-year style (December 23, 2020) but not in the month-year format (December 2020).
Use a comma after the salutation in personal correspondence. (Note below)
Use a comma to separate numbers of four or more digits into groups of three.
Note: When writing formal or business correspondence, use a colon after the salutation.
Example: Dear Chief Justice: NOT Dear Chief Justice,
Until next time, happy writing,