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For the exclusive use of employees of the U.S. Department of State--by Tillyer Associates

Using Commas in Writing

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Use a comma--

--to set off  introductory words and phrases

Because of its modern design, the R.M.S. Titanic was called "unsinkable".
At 883 feet, she was the largest ship the world had ever seen.
At dawn on April 15, 1912, the Titanic and 1,513 of its passengers were gone.

--when a dependent clause comes first in a complex sentence

After it hit an iceberg just before midnight, water began to rush into its flotation chambers.
While there was a radio on board, other ships' radio operators were off duty.
Before the ship sank at 2:20 a.m., 705 passengers were able to get into 13 lifeboats.

--between the clauses linked by a coordinating conjunction (and, or, nor, but, so, for, while,  yet)  in a compound sentence (containing two or more independent clauses)

                Crew members lowered the lifeboats, and the band played calming music.
(Without the comma, the crew members would have lowered the band!)

--to set off a nonrestrictive modifier

NONRESTRICTIVE:   John Jacob Astor, who was an extremely rich man, was among the victims.
RESTRICTIVE:           The man who designed the Titanic was asked to
                                    recommend what to do.

--to set off explanatory material or definitions

E.J. Smith, the captain of the Titanic, ordered the evacuation of the passengers.

--to separate introductory words or phrases, where confusion might result.

As captain, Smith was well liked.

--to set off an interjection or a transition (however, nevertheless, as a result, therefore)

INTERJECTION:        There were far too few lifeboats, unfortunately, for
                                    the 2,208 passengers on board.
TRANSITION WORD: There was a lot of confusion on deck and, as a result,
                                    many of the lifeboats were lowered to the ocean only
                                    partially full.

--to separate series of words, phrases, or clauses.

Women, children and disabled men were allowed to get into the lifeboats first.
The process of untying the lifeboats, filling them with passengers, and lowering them carefully into the frigid sea took nearly two hours.

NOTE: The comma immediately before the and in a series is optional. However, it must be used consistently one way or the other.

--to separate two or more adjectives that describe a noun equally

The sinking ship must have been a devastating, horrid sight!

NOTE: If the adjectives can be reversed, there should be a comma between them. In this example, devastating and horrid are opinion adjectives and have the same value; thus, they need a comma to separate them.

--to separate the day from the year in dates

April 14, 1912
July 4, 1776

NOTE: This is the standard American way to write a date

--to separate long numbers into groups of three from right to left

The population of the U.S. is 22,401,017.
The Titanic weighed 66,000 tons.
It had 2,208 passengers on board.

NOTE: Commas in four-digit numbers are optional. Never use a comma with a year: 1912, 2000.

Do not use a comma--

--to separate two independent clauses…creating a comma splice

WRONG:   Father Francis Brown was a lucky passenger, he got off the ship in 
                                                Queenstown, Ireland.
CORRECT: Father Francis Brown was a lucky passenger since he got off the ship in 
                                                Queenstown, Ireland.
WRONG:    Wallace Hartley was the valiant director of the band on the Titanic, 
                                                some say he kept the band playing gaily as the distraught passengers 
                                                were assigned to lifeboats.
CORRECT:  Wallace Hartley was the valiant director of the band on the Titanic, 
                                                who, some say, kept the band playing gaily as the distraught passengers 
                                                were assigned to lifeboats.

--to separate a subject from its verb

             WRONG:  Convincing the women to leave their husbands and getting them    
                                into the lifeboats as the ship began tipping up at a dangerous angle, 
                                were difficult tasks.
             CORRECT: Convincing the women to leave their husbands and getting them    
                                 into the lifeboats as the ship began tipping up at a dangerous angle
                                 were difficult tasks.

Practice #1 Practice #2 List of Lessons

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