Semicolons ( ; ) are used for two main purposes: to separate lengthy or complex items within a list and to connect independent clauses. They are often described as being more powerful than commas, while not quite as a strong as periods (full stops). That’s why, despite its name, a semicolon should really be thought of as a hybrid between a period and a comma. (After all, it looks just like a period on top of a comma.)
Separating items in a list
When writing lists, we usually use commas to separate the individual elements, as in:
- “I only want ham, cheese, and lettuce on my sandwich.”
However, when one or more items in a list already include commas, we use semicolons to make the division between the items clearer. (If we simply used commas, such lists would be difficult to understand.) For example:
- “Recipients of this year’s awards will include the law firm of Jacobs, Jacobs, and Smith; A1 Consultants, LLC; and several advertising, marketing, and digital media companies.” (correct)
- “Recipients of this year’s awards will include the law firm of Jacobs, Jacobs, and Smith, A1 Consultants, LLC, and several advertising, marketing, and digital media companies.” (incorrect)
- “In less than 10 years, I have lived in Portland, Oregon; Seattle, Washington; Paris, Texas; Denver, Colorado; and Washington, D.C.” (correct)
- “In less than 10 years, I have lived in Portland, Oregon, Seattle, Washington, Paris, Texas, Denver, Colorado , and Washington, D.C.” (incorrect)
Numbered, lettered, and vertical lists
We usually only use semicolons in lists if the individual items in the list use commas internally. However, if we want to number or letter the lists (for instance, to clarify the order in which a list must be followed or to highlight its items), we use semicolons to make them easier to read. For example:
- “Your assignment for the evening is as follows: (1) interview an older relative about his or her experiences growing up; (2) write down your own experiences for the same time period; (3) write a one-page report that compares and contrasts your experiences to those of your relative.”
- “We’ll need four things for the upcoming audit: (a) copies of all bank statements over the last year; (b) a letter from the bank confirming the company’s signatories; (c) any receipts for business-related purchases made this year; (d) a profit and loss report for the year to date.”
Some writers also prefer to use semicolons when they write lists vertically (whether using numbers, letters, bullet points, or nothing at all). For instance:
“There are a few tasks we need to address at the next meeting:
- reaching a wider consumer demographic;
- developing a stronger presence on social media; and
- deciding on the slogan for our new advertising campaign.”
However, there is a wide variety of opinion regarding when and how (and even if) to punctuate and/or capitalize elements in a vertical list. For the most part, this comes down to stylistic preference rather concrete “rules” about the structure, so check with the style guide of your school or employer.
Joining independent clauses
We can also use semicolons to combine independent clauses that have an inherent relationship with one another (such as contrast or causation) into a larger compound sentence. The semicolon is used in place of a period to bridge the gap between the end of one sentence and the beginning of another. We can see in each of the following examples how either a period or a semicolon could be used:
- “I hope the traffic isn’t too bad. I don’t want to be late for the movie.”
- “I hope the traffic isn’t too bad; I don’t want to be late for the movie.”
- “Don’t run near the pool. You might slip and hurt yourself!”
- “Don’t run near the pool; you might slip and hurt yourself!”
- “My Great Aunt Winifred was an amazing woman. She once traveled to the North Pole on a bobsled all by herself.”
- “My Great Aunt Winifred was an amazing woman; she once traveled to the North Pole on a bobsled all by herself.”
By using semicolons instead of periods, we express a relationship between the two clauses that is not as obvious when we use periods and treat them as separate sentences.
Note that we could also use commas and coordinating conjunctions to connect the two clauses and explicitly describe the relationship between them. For instance:
- “I hope the traffic isn’t too bad, for I don’t want to be late for the movie.”
- “Don’t run near the pool, or you might slip and hurt yourself!”
- “My Great Aunt Winifred was an amazing woman, as she once traveled to the North Pole on a bobsled all by herself.”
While grammatically correct and perfectly acceptable, forming the sentences this way expresses a very specific relationship between the clauses. By using semicolons instead to imply the relationship, the sentence flows more naturally and the reader is allowed to be more engaged in the interpretation of its meaning.
Using semicolons with coordinating conjunctions
Generally speaking, we do not use semicolons with coordinating conjunctions to connect independent clauses. The pause created is too strong, and we would usually just use a comma to link them together.
However, in certain cases when the first independent clause is particularly lengthy or complex and already contains commas internally, we can use a semicolon to make the pause between clauses easier to understand. For example:
- “It was only after discovering the financial arrears of the company, which amounted to nearly $1 million, that we realized we would need to reorganize its entire infrastructure; but we had little to no means of making any further investments, with so much debt already outstanding.”
Be wary of making the sentence too cumbersome by joining two complex clauses with a semicolon, however. It might be preferable in such instances just to use a period and divide them into two separate sentences.
Using semicolons with conjunctive adverbs
While it is only under certain conditions that we may use a semicolon with a coordinating conjunction, another type of conjunction is almost always paired with a semicolon. These are known as conjunctive adverbs, and they are used to describe a relationship between the clauses they conjoin.
Conjunctive adverbs are typically used at the beginning of the second clause (immediately after the semicolon), followed by a comma. Note that while we can use a period instead of a semicolon with conjunctive adverbs, we cannot use a comma to join the clauses. For example:
- “Jen hadn’t enjoyed the play; therefore, she didn’t recommend it.” (correct)
- “Jen hadn’t enjoyed the play. Therefore, she didn’t recommend it.” (correct)
- “Jen hadn’t enjoyed the play, therefore, she didn’t recommend it.” (incorrect)
If we choose to separate the two clauses with a period, we must remember to capitalize the conjunctive adverb, since it is the first word in a new sentence.
Choosing a conjunctive adverb
To choose the conjunctive adverb best suited to join two clauses together, we must consider the relationship between the first and second clause. Let’s look at the example again:
- “Jen hadn’t enjoyed the play; therefore, she didn’t recommend it to her friend.”
The second clause is a result of the first clause. Jen hadn’t enjoyed the play, and that is the reason that she didn’t recommend it to her friend. So, when we connect the two clauses, we choose a conjunctive adverb (therefore) that makes this cause-and-effect relationship clear. Think about how the relationship between these two clauses is different from the previous example:
- “Jen hadn’t enjoyed the play. She recommended it to her friend.”
We still have two independent clauses, but now the relationship between them is different. Jen hadn’t enjoyed the play, but recommended it to her friend anyway. We can no longer use the conjunctive adverb therefore, because we are no longer dealing with cause and effect. Instead, we need to choose a conjunctive adverb like nevertheless, which is used to express unexpected results:
- “Jen hadn’t enjoyed the play; nevertheless, she recommended it to her friend.”
There are many different conjunctive adverbs we can use, depending on the relationship we want to describe.
When not to use a semicolon
Although semicolons function in ways similar to both commas and periods, they do not have the exact function of either: they are stronger than a comma but weaker than a period, so it is not always appropriate to substitute one for the other.
Don’t use semicolons with dependent clauses
Because dependent clauses rely on independent clauses to make sense, the link between them must be expressed by either a comma (if a dependent clause is used at the beginning of a sentence) or no punctuation at all (if a dependent clause comes after an independent clause and does not require a pause). Using a semicolon would create too strong a break between the clauses to maintain their cohesion. For example:
- “Whenever I travel to Paris, I always stay in the same hotel overlooking the Seine.” (correct)
- “Whenever I travel to Paris; I always stay in the same hotel overlooking the Seine.” (incorrect)
- “Shares in the company fell as details of the corruption scandal emerged.” (correct—no punctuation needed between clauses)
- “Shares in the company fell; as details of the corruption scandal emerged.” (incorrect)
- “We’d be happy to lend you the money, provided that you have something you can use as a collateral.” (correct—use of a comma is optional in this case)
- “We’d be happy to lend you the money; provided that you have something you can use as a collateral.” (incorrect)
Don’t use semicolons between unrelated independent clauses
Using semicolons can add sophistication to a sentence by implying a relationship between two independent clauses. However, we must be sure that such a relationship exists in the first place; otherwise, a semicolon will not be appropriate. Consider, for example, these two simple sentences:
- “Tomatoes are a fruit; they were once considered poisonous.” (incorrect)
The fact that tomatoes are a fruit is not directly related to the fact that they were once considered poisonous. Therefore, joining the two clauses with a semicolon creates a confusing sentence, because it implies a relationship between the clauses that does not necessarily exist. Therefore, we should use a period and leave the clauses as two separate sentences:
- “Tomatoes are a fruit. They were once considered poisonous.” (correct)
Using semicolons with other punctuation
Because semicolons are used to join lists or independent clauses, they are usually not used alongside other punctuation marks. The only exceptions to this are certain uses of periods and quotation marks.
A semicolon is most often used as an alternative to a period. However, when a period is used to mark an abbreviation that appears at the end of a clause or in a list, then it becomes necessary to use both punctuation marks together. For example:
- “We are open every week Mon. through Fri.; we are closed on weekends and public holidays.”
- “I’ll be away for most of Jan.; you can still reach me by email, though.”
With quotation marks
When a semicolon is used after a quoted element of text, it is important to remember that it should appear outside of the ending quotation mark. For instance:
- He says he has been “working on a solution”; what exactly that means, however, is unclear.
- I have a few suggestions for the story: a stronger emphasis on character development; a new love interest, whom the protagonist could meet during the chapter “Reunions”; and less historical background information so the story maintains a faster pace.