An Introduction to Using Commas

Commas are probably the most important punctuation mark other than the period. They could be using for many purposes like the following: to separate items in a list, to separate compound sentences before conjugating words like “because, so, and, or,” etc; to separate citations, they can be used in place of dashes to separate clauses, can be used after transitions words, can be used to separate complex sentences, and to separate cities from states in addresses.

For separating items, it is important that you use “and” or “or” before the last item of a list: I have three dogs named Larry, George, and Chester.

For using commas in compound sentences that require conjugation, it is important that you put the comma before the conjugating verb: “I can be mad as much as I want, but there is nothing I can do.”

For using commas in transition words and clauses, just put the comma after the transition word. The transition sentence either can be a separate sentence or separated from another sentence by a semicolon: “However, I couldn’t find any other truffles in the forest.”

Commas used in place of dashes are there to separate clauses. They are used before verbs like “ which” or “what” : “ We were in an igloo, which is a small shelter made up of ice.”

One of the most common ways we use commas are to separate a city from a state. For example, you can use the comma in “Denver, CO.” They are used in a similar way to separate parts of dates: September 27, 2007. However, you should be aware that dates are formatted in a variety of different ways in different style guides.

As you proofread, you want to ask yourself the following questions:

1. Is this comma necessary in order to understand this sentence?
2. Is the information the comma surrounds essential or extra (nonessential)?
3. Does the sentence include a series of three or more?
4. Are the items in the series separated by conjunctions?
5. Am I introducing a quote or incorporating a quote? (She said, “I…” or the dog “ran across the field”)

6. Does the comma separate ideas that should be connected?
7. Does this sentence need a comma added to it?

When to use a comma(,)
1. When listing items in a series.
a. Example: The shirt was red, blue, and orange.
2. When using an introductory phrase.
a. Example: Regardless, he still should’ve called her.
3. To separate two independent clauses.
a. Example: He went shopping with his friend, and also went to the movies.
4. To set off parenthetical elements.
a. Example: The Mississippi, which is the largest river in the US, was where we went on vacation.
5. The adverbial clause.
a. Example: I knew that it was going to rain, because my friend was watching the weather channel and told me.
i. If the comma was not in the sentence it makes it sound as though it was going to rain BECAUSE my friend was watching the weather channel.





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