Commas & Semi-colons

graphic of a comma mark

Two Quick Comma Rules:

1. Use with a Coordinating Conjunction: (for, and, nor, but, or, yet, so)

2. Use to set off introductory words, phrases, or clauses: lets the reader know that the main subject and main verb of the sentence come later. No matter what size they are (small, medium, or large), an introductory bit cannot stand alone as a complete thought. It simply introduces the main subject and verb.

When Do You Use a Comma?

  1. Use commas to separate independent clauses when they are joined by any of these seven coordinating conjunctions: and, but, for, or, nor, so, yet.
  1. Use commas after introductory a) clauses, b) phrases, or c) words that come before the main clause.
  1. Use a pair of commas in the middle of a sentence to set off clauses, phrases, and words that are not essential to the meaning of the sentence. Use one comma before to indicate the beginning of the pause and one at the end to indicate the end of the pause.
  1. Use commas to separate three or more words, phrases, or clauses written in a series.
  1. Use commas to separate two or more adjectives that describe the same noun.
  1. Use commas wherever necessary to prevent possible confusion or misreading

Commas for Introductions or Non-Essentials

Use commas to introduce or set aside small, mediums, or large words/phrases.

Short: One-word introductions:

  • Generally, extraterrestrials are friendly and helpful.
  • Moreover, some will knit booties for you if you ask nicely.

Medium: Often these are two to four-word prepositional phrases or brief –ing and –ed phrases:

  • In fact, Godzilla is just a misunderstood teen lizard of giant proportions.
  • Throughout his early life, he felt a strong affinity with a playful dolphin named Flipper.
  • Frankly speaking, Godzilla wanted to play the same kinds of roles that Flipper was given.
  • Dissatisfied with destruction, he was hoping to frolick in the waves with his Hollywood friends.

Long: You can often spot these by looking for key words/groups such as although, if, as, in order to, and when:

  • If you discover that you feel nauseated, then you know you’ve tried my Clam Surprise.
  • As far as I am concerned, it is the best dish for dispatching unwanted guests.



Use a semi-colon when you want to combine two sentences (or independent clause) that relate to one another, and you don’t want to use a coordinating conjunction: and, but, or, for, yet, nor, so. When a conjunctive adverb connects two independent clauses, it is preceded by a semicolon and followed by a comma.

Two sentences: Local clinics have been losing key employees due to tighter budgets. These cuts have made it difficult to perform routine tasks.

Semi-colon: Local clinics have been losing key employees due to tighter budgets; these cuts have made it difficult to perform routine tasks.

Coordinating conjunction: Local clinics have been losing key employees due to tighter budgets, and these cuts have made it difficult to perform routine tasks.

Using a semi-colon

Conjunctive Adverbs

Use a semi-colon when combining two sentences (or independent clauses) with a conjunctive adverb: however, therefore, thus, moreover, nevertheless, furthermore.

 Combining two independent clauses:

Local clinics have been losing key employees due to tighter budgets; however, our clinic just hired a new technologist.

Clinics will suffer with their loss of staff; nevertheless, they must work hard to ensure their patients get the best care.

With one independent clause: You can also use conjunctive adverbs to connect ideas within a single independent clause. In this case, you use a comma(s) instead of a semi-colon. If a conjunctive adverb is used in any other position in a sentence, it is set off by a comma or commas.

The physician administered the wrong medication, therefore killing the patient.

Consequently, the physician was removed from the clinic.

The head administrator, however, explained later that the patient had withheld information about drug allergies.

Conjunctive Adverbs

  •    accordingly      furthermore       moreover                 similarly                         although
  •    also                   hence                 namely                        still                                  yet
  •    anyway             however            nevertheless                then                              that is
  •    besides            incidentally       next                          thereafter                      subsequently
  •    certainly            indeed               nonetheless                therefore                      conversely
  •    consequently    instead              now                            thus                        comparatively
  •    finally                likewise            otherwise                  undoubtedly                   currently
  •    further               meanwhile          in fact                      on the other hand           in contrast

Working with Conjunctive Adverbs

Last Updated May 9, 2017