A semicolon can be used to connect two closely related independent clauses (parts of a sentence that could also stand as separate sentences).
Semicolons are also used to separate list items that contain internal punctuation such as commas and dashes.
The semicolon is often described as a punctuation mark that is stronger than a comma and weaker than a full stop, but it is not interchangeable with other punctuation marks.
Connecting independent clauses
An independent clause is a grouping of words with a subject and a verb that can stand as a complete sentence on its own. A semicolon marks a break between two independent clauses while signaling a close relation between them.
An easy way to check if your semicolon is grammatically correct is to try replacing it with a period.
The sentence is equally grammatically correct if we split it into two sentences. Since the two clauses convey closely related content, the semicolon is an appropriate choice to link them.
Separating items in complex lists
Items in a list are usually separated with commas.
However, if the items themselves contain commas (or other punctuation such as dashes), semicolons are used instead of commas to divide them. This helps readers keep track of the division between the complex items within the list.
Common semicolon mistakes
Semicolon where a comma should go
It’s important to note that a semicolon isn’t just a “stronger” version of a comma. They have different grammatical functions, and using them interchangeably often results in errors.
- The journal would not even consider the article without a properly formatted reference list; which it did not have.
- The journal would not even consider the article without a properly formatted reference list, which it did not have.
Remember that a semicolon connects two independent clauses that are able to stand as complete sentences on their own. In the above example, the dependent clause “which it did not have” cannot form a complete sentence on its own, so it must be joined to the main clause with a comma.
Comma where a semicolon should go
A related mistake is using a comma instead of a semicolon to join independent clauses. This creates an error called a comma splice.
- The professor is currently on sabbatical, she is in Italy researching for her book on Renaissance ivory carvings.
- The professor is currently on sabbatical; she is in Italy researching for her book on Renaissance ivory carvings.
Both parts of the sentence are independent clauses, so a comma alone is not sufficient to join them. Instead, they must be split into two sentences, joined with a semicolon, or joined with a conjunction.
Semicolon where a colon should go
Semicolons and colons look similar, but they have different functions. Another common mistake is using a semicolon where a colon should go. Semicolons separate items within a list, while a colon precedes and introduces a list.
- He took three things on the hike; his lunch, his binoculars, and his trusty walking stick.
- He took three things on the hike: his lunch, his binoculars, and his trusty walking stick.