Grammar:

Comma Use

In this lesson, you’ll learn some basic rules for comma use.

Comma Basics

Commas have many roles in writing. In this lesson, we will discuss four of those roles.

Commas and Introductory Words and Phrases

A comma should be used with introductory words and phrases. It is important to put a comma after introductory words and phrases because they signal a transition or provide more information about an idea.

Let’s look at the following passage:

Rita arrived to work on time. However, she forgot to attend her first meeting.

In the passage above, the writer moves from the first sentence to the second sentence by using the word however and a comma. In this way, however acted as an introductory word—leading the reader to the next sentence.

Let’s look at another passage:

We prefer bright colors for our website. For example, we like yellow and light blue.

In the passage above, the writer uses the introductory phrase for example and a comma to move to the next sentence, where the writer provides an example.

Here are some common introductory words and phrases:

Introductory Words and Phrases to Be Used with a Comma

Introductory Words	Introductory Phrases
Unfortunately However Luckily Finally First Second Next Also	In the meantime For example In contrast In the end Of course

Commas in Lists

A comma should be used to separate three or more items listed in a sentence. These listed items can be single words or whole phrases. Commas are placed after each item in the list. Usually, it is best to place the word and before the last item in a list.

Let’s look at the following example:

I purchased paper, ink, pens, and staples at the supply store.

In the above example, the items that were purchased were listed with a comma after the first three items, and then the writer used the word and before listing the last item.

Let’s look at an example where phrases are used in a list:

Yesterday she washed ten windows, made sixteen beds, and cleaned eight bathrooms.

In the above example, the tasks that were completed were listed with a comma after the first and second items, and then the writer used the word and before listing the last task.

Commas with Names of Places

A comma should be used between the name of a city and state/nation.

Let’s look at the following examples:

They will be traveling to a conference in Denver, Colorado.

We want to start construction in London, England.

If the names of the city and state/nation are in the middle or beginning of a sentence, a comma should also be placed after the state/nation.

See the following examples:

They will be traveling to a conference in Denver, Colorado, during the summer season.

London, Englad, is the company’s birthplace.

Commas and Dates

A comma should be placed between the day and year in a date.

See the following example:

Our childcare business opened on August 10, 1999.

If the date is in the middle or beginning of a sentence, a comma should also be placed after the year.

See the following examples:

August 10, 1999, is the day our childcare business opened.

No comma is necessary if the day of the month is not mentioned.

See the following examples:

June 2001 was an important time in our company.

He has been working here since September of 2000.