Do not join two complete sentences with a comma (also called comma splice). You can fix it by adding a semicolon, placing a period, or using a conjunction.
Do not join two complete sentences with a comma (also called comma splice).
I love Thai soups, they are tasty and delicious.
There are three simple solutions to fix a comma splice:
- Adding a semicolon:
I love Thai soups; they are tasty and delicious.
- Placing a period:
I love Thai soups. They are tasty and delicious.
- Using a conjunction:
I love Thai soups because they are tasty and delicious
Contents
1. What Is a Comma Splice
It is incorrect to join two independent clauses with a comma—more technically known as a comma splice.
I went to Miami, my father was sick.
As a quick reminder, an independent clause is group of words that has a subject and a verb and can stand alone ("I went to Miami" and "my father was sick" in the example above)
How can you fix a comma splice? There are three ways to avoid a comma splice, which are essentially based on the following punctuations marks (or parts of the speech):
- semicolons
- periods
- conjunctions
2. When to Use a Semicolon to Fix a Comma Splice
A semicolon is the proper punctuation mark to join two or more clauses that are grammatically complete.
You should study Chinese; it is important to learn it for business.
You should study Chinese, it is important to learn it for business.
Typically, semicolons are a good alternative to a comma splice since they narrow the gap between two closely linked sentences.
Come with me to Spain; we'll have fun.
The main advantages of semicolons over periods and conjunctions are:
- A semicolon expresses the close relationship between two statements in a way that a period does not attempt.
- Semicolons lead to briefer and therefore more forceful statements.
If the second clause is preceded by an adverb, such as "therefore", "then", "besides", "accordingly", etc., the semicolon is still required.
Olive oil has strong anti-inflammatory properties; besides, it contains large amounts of antioxidants.
More examples:
- Rebecca wants to go to New Zealand; she'd love to explore its striking natural beauty.
- James is thinking about learning computer programming; he needs to get a higher paying job.
- I don't want to go to the restaurant tonight; I'm not dressed for a date.
3. Using a Period
We can use a period, instead of a semicolon, to avoid a comma splice.
Barbara watched the movie from beginning to end, she loved it.
Barbara watched the movie from beginning to end. She loved it.
The example above illustrates the advantages of using a period when the second sentence, reflecting the natural outcome of a previous statement, is brief and conclusive.
More examples:
- I went to the best and cleanest beach in Hawaii (maybe in the world). It was amazing!
- In my opinion, you should invest in commodities right now. They are cheap.
- I'm going to walk you through two different ways of accomplishing this. Come with me.
4. Using a Conjunction to Avoid a Comma Splice
4.1 Using Coordinating Conjunctions
In many situations, you can fix a comma splice by using a coordinating conjunction (and, or, but, nor, yet, so, for).
My wife went to the grocery store, she bought some oranges.
My wife went to the grocery store, and she bought some oranges.
Why do we use a comma before and in the example above?
In general, we should use a comma before a coordinating conjunction to join two independent clauses.
My girlfriend eats a lot, but she can't gain weight.
Note that we must use a comma before "but" because both clauses are independent. However, if the subject does not appear in front of the second verb, a comma before the conjunction is generally unnecessary.
Last year, I went to India and learned yoga from an experienced teacher.
More examples:
- My brother is tall, but he doesn't like to play basketball.
- Did Albert take the bus, or did he drive home?
- My husband and I went to Bangkok, and we visited the Grand Palace.
4.2 Using Subordinating Conjunctions
Some of the most common subordinating conjunctions are "because", "when", "if", "since", "until", "while", "although", etc. These conjunctions are commonly used to join two ideas by joining an independent clause and a dependent clause.
Study this example:
I went to Boston, my uncle was sick.
We can easily fix this comma splice by using a subordinating conjunction.
I went to Boston because my uncle was sick.
Note that we do not need a comma in front of "because" in the sentence above. Actually, we do not typically put a comma before a subordinating conjunction in mid-sentence.
I'll go to Chicago if you come with me.
However, when introducing a sentence with a subordinating conjunction, use a comma to separate both clauses.
If you come with me, I'll go to Chicago.
Another example.
Because my uncle was sick I went to Boston.
Because my uncle was sick, I went to Boston.
More examples:
- The unemployment rate is relatively high, although regional variations are notable.
- I feel more relaxed when I practice yoga with my friends.
- If you go to Spain, you have to try paella.
5. Exceptions
A comma is acceptable, and sometimes even preferable, if both clauses are very short and have a similar structure.
Man proposes, God disposes.
Here today, gone tomorrow.
6. Conclusion
Using a comma to join two complete sentences (comma splice) is incorrect in English; nevertheless, you can follow one of these strategies to avoid it.
- Replacing commas by semicolons helps narrow the gap between two closely linked sentences.
- Placing a period instead of a comma is particularly useful to emphasize the second part of a thought.
- Using a coordinating conjunction (and, or, not, but, yet, for, so) can be used to join two independent clauses.
- Using a subordinating conjunction ("when", "because", "until", "if", etc.) can be used to signal a time, space, or cause-and-effect relationship between two clauses.
7. References
(1) Kaufman, Lester; Straus, Jane. The Blue Book of Grammar and Punctuation. Chapter 2 (punctuation).
(2) Strunk JR., William; White, E.B. The Elements of Style. Chapter 1 - Elementary Rules of Usage.