1. Commas How to use commas correctly How to avoid comma splices &
fused (run-on) sentences
Using semicolons
USING COLONS
For comma exercises, please visit Purdue OWL:
For more comma rules, please visit Grammar Girl:
For additional instruction on this topic, refer to the Grammar module in D2L.

2. Commas Matter!

3. When to Use Commas
Before a conjunction (and, but, for, nor, or, so, yet) that joins two independent clauses:
I’d like to visit the mall, but let’s go to lunch first.
After an introductory phrase:
After lunch, I’d like to visit the mall.
After a transitional word or phrase:
First, we’ll go to lunch. Next, we’ll go to the mall.
To separate elements in a list:
I want to visit Italy, France, and Spain.
Remember FANBOYS. It is the acronym for all of the conjunctions (for, and, nor, but, or, yet, so).
APA style requires that a comma is used before the final element in a list. In others forms of writing (like news articles), the comma before the final element is not required and is therefore often left out; do not confuse this with the requirements of APA style. Correct: I want to visit Italy, France, and Spain. Incorrect (in APA style): I want to visit Italy, France and Spain.

4. Commas set off Nonessential Clauses
When there is a single entity that you could be referring to, you need to set off nonessential information about that entity:
I’d like to visit my grandma, Helen.
This sentence tells the reader that you have only one grandmother, and her name is Helen.
When there is a more than one entity to which you could be referring, its identity is essential information about that entity, and it does not get set off by a comma:
I’d like to visit my grandma Helen.
This sentence tells the reader that you have more than one grandmother, but the one you want to visit is Helen.
The same information may be essential or nonessential, depending on the context.
If I have only one sister, then including her name in the sentence is not necessary to clarify which sister I’m referring to:
My sister, Amy, is coming to visit.
This sentence provides additional information about my sister (her name), but that information is not essential because you can’t confuse Amy with any other person if I have only one sister.
Thus, the correct use of commas in the sentence above conveys the information to my reader that I only have one sister.
If, on the other hand, I had more than one sister, then including her name in the sentence would be necessary to clarify which sister I was referring to:
My sister Amy is coming to visit.
This sentence provides essential information about which sister is coming to visit. It is essential because you wouldn’t know which of my sisters was coming to visit if I didn’t include her name.
Thus, the correct lack of commas in this sentence conveys the information to my reader than I have more than one sister.
Another way the essential clause is described is as a restrictive clause. It restricts the possible entities (multiple sisters) to the specific entity you actually intend.

5. So as an explanation
In some sentences, the word so is used to introduce an explanation for the behavior that occurred prior to the word so:
We ate quickly so (that) we would not be late for the movie.
She worked late so (that) she could finish the assignment before the deadline.
In these cases, so is not introducing an independent clause; the explanation that follows is a dependent clause. The word that in parentheses is added to help you distinguish when a comma is and is not required before so.
When so introduces an independent clause, it does take a comma:
She finished the report, so she took the next day off.
In this situation, the word so implies the same thing as the word therefore.
When so introduces a dependent clause, it does NOT take a comma:
She finished the report so (that) she could take the next day off.
In this situation, the word so implies the same thing as the phrase in order that.
Another way of describing this use of so is that it is followed by a restrictive clause, a clause that provides an explanation that is one of the many possible explanations for why she finished the report.

6. Comma Splices
A comma splice incorrectly joins two main (i.e., independent) clauses with a comma.
Incorrect: I like going to the mall, we are having lunch first.
One way this error can be corrected by adding a coordinating conjunction:
Correct: I like going to the mall, but we are having lunch first.
Check out this short comma splice exercise:

7. Fused Sentences (Run-on)
A fused sentence contains two main clauses with no punctuation:
Incorrect: I like going to the mall we are having lunch first.
When used correctly, commas (among other forms of punctuation) can fix a fused, or run-on, sentence.
Correct: I like going to the mall, but we are having lunch first.
Check out this short fused sentence & run-on exercise:

8. How to Use Semicolons
To link two independent clauses to connect closely related ideas:
I would like to visit Paris; my sister would rather visit Spain.
To link clauses connected by a conjunctive adverbs or transitional phrase:
I would like to visit Paris; however, my sister would rather visit Spain.
Check out this additional info on semicolons:
When a semicolon is used to join two or more ideas (parts) in a sentence, those ideas are then given equal position or rank.
Incorrect: I would like to visit Paris, my sister would rather visit Spain. Correct: I would like to visit Paris; my sister would rather visit Spain. Both parts of the sentence are independent clauses, and commas should not be used to connect independent clauses if there is no coordinating conjunction. When doing so, the mistake is known as a comma splice.
Incorrect: Some people prefer to write with pens, however some prefer to write with pencils. Correct: Some people prefer to write with pens; however, some prefer to write with pencils.
The conjunctive adverb however signals a connection between two independent clauses, and commas should not be used to connect independent clauses if there is no coordinating conjunction.

9. How to Use Colons
Use colons between a grammatically complete introductory clause and a final clause that extends the preceding thought.
She enjoyed many types of music: jazz, pop, and country.
If the clause following the colon is a complete sentence, it begins with a capital letter.
The researchers agreed: The participants were drowsy after taking the experimental drug.
Do not use a colon after an introduction that is not an independent clause or complete sentence.
Incorrect: She wants to go to: Spain, Paris, and Italy. Correct: There are a few places she wants to visit: Spain, Paris, and Italy.