Contributor: Aaron Smale

Semicolons are often used to join parts of a sentence together to establish variety and link related ideas. Unlike a colon, which separates an independent clause from descriptive information, a semicolon links independent clauses of equal standing. Below are some helpful tips on how to use semicolons effectively and appropriately to strengthen sentence structure and variety.

When to use a semicolon

When joining two closely related independent clauses into one compound sentence:

• Deadpool is a snarky assassin within the Marvel universe; he is affectionately known as the “Merc with a Mouth.”
• In this example, notice how a comma and a conjunction (e.g. and) or a period could take the place of the semicolon, but the semicolon implies a stronger connection between the two clauses.

It is important to use a semicolon whenever the conjunction has been left out since inserting a comma alone will create a comma splice (two independent clauses joined together as if one is a dependent clause):

• Deadpool is a snarky assassin within the Marvel universe, he is affectionately known as the “Merc with a Mouth.”
• Using a comma here disrupts the reader. It implies a relationship between the two independent clauses that is not accurate.

When using a transitional expression such as therefore, for instance, furthermore, in addition, as a result, etc. to link independent clauses:

• Though he was first introduced as a super-villain in the Marvel universe, Deadpool has evolved into an antihero that often breaks the fourth wall; as a result, comic writers often give Deadpool humorous and playful dialogue.
• As a hardened mutant assassin, Deadpool can’t afford to fear death; therefore, he courts the personification of death, Lady Death, on several occasions.

Though the transitional phrase/expression in the above examples directly follows the semicolon, note that the semicolon still goes between the clauses even if the expression appears in the middle or at the end of the second independent part:

• Deadpool will often serenade Lady Death and try to sweep her off her feet; Lady Death, however, often leads him into comical traps and abandons him in awkward social situations.

To prevent confusion when listing items in a series with internal punctuation:

• Deadpool has clashed with other heroes and villains in cities like San Francisco, California; New York, New York; and El Paso, Texas.
• Without the semicolons to separate the cities like this, the reader has to manage the pairings, creating a potential lack of clarity. With the semicolons at the major breaks between states, the writer helps the reader maintain distinctions.

When not to use a semicolon

When separating an independent clause from a dependent clause or introducing a series/list— use a comma instead:

• Deadpool’s mutant power is his incredible healing factor, which allows him to withstand injuries beyond normal human capacity.
• Deadpool’s arsenal includes a variety of different weapons: katanas, assault rifles, knives, grenades, and banana cream pies.

When using a conjunction like and, but, for, yet, so, etc. to connect independent clauses. A comma is required with the conjunction:

• Deadpool’s allegiances often change by the hour, but he always puts his motivations first.

Between an appositive that is directly followed by the word that the appositive refers to—use a comma:

• Deadpool will often team up with Cable, a mutant freedom fighter from the future and the son of Scott Connors and Jean Grey.