Using Semicolons

The semicolon is another important tool you can use when you write. There are two ways to use this punctuation mark: as a connector between two sentences and as a supercomma.

Connecting Two Sentences

The semicolon is most often used to connect two sentences. Obviously, the sentences ought to be relatively close in content, but other than that you can connect any two sentences with a semicolon.

The following diagram may help you remember this usage:

sentence ; sentence

As a communicator, you are always putting together complex items in your prose and showing how they relate to one another. A semicolon is an economical way to join two sentences, and therefore two ideas, so that your reader sees the relationship. For example, you may write any of the following sentences:

Jim is a good typist; he makes few mistakes.

The AFC Corporation is an excellent company to invest in; its investments have risen sharply and steadily over each of the last ten years.

Ms. Sanchez is a successful real estate salesperson; however, she was unable to sell her own house.

Each of the three examples above contains two sentences glued together by a semicolon. The second part of each sentence makes a comment on the first. Certainly, each sentence could be written as two sentences, but you wouldn’t be expressing the close relationship between the two parts that you do when you use a semicolon. With two separate sentences, the reader must stop at the period of the first sentence and then begin to read the second; with two sentences connected by a semicolon, the reader does not come to a full stop and, therefore, the relationship seems that much closer. Also, this type of sentence allows you to express your ideas economically.

The important point to remember is that you must have a complete sentence on both sides of the semicolon. If your second sentence begins with a conjunction (and, but, or, etc.), you do not need a semicolon because the conjunction and the comma that usually goes with it are equivalent to a semicolon. Instead, combine two full sentences with the semicolon.

Sometimes a sentence may begin with words like however, therefore, and nevertheless. If your second sentence begins with one of these words, and if it is indeed a full sentence, you still must use a semicolon to connect the two. The sentence about Ms. Sanchez illustrates this use.

A word of caution: never glue two sentences together with only a comma. Grammarians call this sentence error a comma splice. Here is an example of two sentences connected with only a comma:

The banking community became quite upset at the rise in the prime rate, bankers felt that they would ultimately lose a considerable amount of money.

A comma splice is considered ungrammatical because the reader begins reading the second sentence before realizing that the first sentence is completed. Readers are used to stopping at the end of a sentence, and they become disoriented when they find that they have unknowingly left one sentence and entered a new one. This is why effective writers avoid the comma splice. Here are two additional examples of comma splices:

Ms. Linccini is a fine worker, she meets all her deadlines.

Our sales have increased by twenty percent, our inventory has been reduced by thirty percent.

Each of the examples above constitutes two sentences glued together with a comma. You can correct a comma splice by inserting a semicolon between the two sentences, by adding a conjunction to your comma, or, of course, by punctuating them as two sentences. Whichever way you choose, however, you must make sure your final drafts do not contain comma splices.

There is one instance in which a comma splice is considered acceptable. Occasionally, you may have a list of items that could stand alone as full sentences. You may use commas to attach these items so long as it is clear to the reader that this is a list of relatively equal items. Here is an example:

I opened the safe door, I took out the money pouch, and I concealed it in my desk drawer.

The example above shows a list of three items and illustrates a step-by-step process. Even though the items all constitute full sentences, it is acceptable to use commas to attach them but only because they are members of a larger list. If you are unsure about using commas to connect sentences in a list, perhaps it is best to rewrite the sentence. Do, however, stay alert for any two sentences in your prose that are connected by only a comma.

Related to the comma splice is the run-on sentence. Run-on sentences, often called “fused” sentences, are two sentences punctuated as if they were one. In other words, a run-on is a comma splice without the comma--two sentences smashed together with no punctuation between them. Here are two sample run-ons:

Chu Lie is the foreman Joseph Garcia is the line boss.

I knew that the new personnel policy would cause problems the union is reacting quite vehemently.

As you can see, each of the two samples above is composed of two sentences. The writer should have connected the sentences with a semicolon or punctuated them as separate sentences. Again, you don’t have to worry about such matters until the proofreading stage, but you must make sure your final draft doesn’t contain run-on sentences.

Semicolon as Supercomma

As you know, you normally separate the members of a list with commas, as in this sentence:

I have just bought shares in IBM, USAG, and ITT.

The commas let the reader know where one item ends and the next begins. Sometimes, however, you have a list of complex items and one (or more) of the items already contains a comma. In such a case, the reader is likely to get confused about what is really a member of the list and what is not. You can avoid this confusion by making the semicolon a sort of “supercomma.”Look at the sentence below to see how the supercomma works:

Suncom Corporation has subsidiaries in four cities: New York, New York, Wilmington, Ohio, Houston, Texas, and San Francisco, California.

This sentence contains so many commas, both between the members of the list and within them, that readers are likely to become confused. Instead, you can make the semicolon a supercomma between each of the members so that your meaning is clear:

Suncom Corporation has subsidiaries in four cities: New York, New York; Wilmington, Ohio; Houston, Texas; and San Francisco, California.

The second sentence is clearer than the first because the reader knows exactly where members of the list begin and end. You probably will not need to use a semicolon as a supercomma often, but if your sentence contains a list of items, one (or more) of which already contains a comma, you can clarify your meaning by using the supercomma.

© Gary A. Olson, 1980