BUS603: Managing People

If you place commas wherever you feel like the reader should take a breath - or simply because the sentence seems long - you're probably committing comma errors. Instead, take a rule-based approach to place commas precisely and confidently.

10.1 Use commas around nonessential words or phrases.

This keeps your sentences flowing smoothly and helps the reader capture your meaning the first time through.

Consider two additional examples.

You might think the two sentences communicate exactly the same thing. You'd be wrong. The difference is indicated by the commas. In Sentence 1, the commas indicate that "Wayne" is nonessential information. In other words, the author has only one son and his name happens to be Wayne. In Sentence 2, the lack of commas indicates that "Wayne" is essential information. The author clearly has more than one son but is talking about the one (Wayne) who is an econ major.

Have you ever wondered whether to use "that" or "which" in a sentence? Many writers mistakenly use them interchangeably. Furthermore, using "that" and "which" correctly requires some skill with commas.

Here's the rule: "that" is used with restrictive clauses. Restrictive clauses are "must-have" information, without which the reader won't understand the meaning of the sentence. "Which" is used when the clause is non-restrictive: it contains "nice-to-have" information that is not essential to the meaning of the sentence. The following video clarifies the difference:

Notice the presence of commas with "which," and their absence with "that".

10.2 Use commas after introductory words, phrases, and clauses.

Commas prevent the intro act from stealing the show from the main act. Check out these examples:

When a dependent clause is shifted to the end, the sentence no longer needs a comma:

10.3 Use commas to separate clauses.

Some sentences have only one subject and verb (i.e., one independent clause). Others have multiple clauses and a few phrases thrown in.

The following examples show how a simple sentence becomes more complex with the addition of clauses. Note how commas are used to separate the clauses.

The commas are exaggeratedly large in these sentences to highlight their placement. As discussed in 10.2 above, commas are used to separate an introductory dependent clause from an independent clause (see Sentence 3).

Note also that a comma separates two independent clauses (see Sentence 2). In sentences that contain two independent clauses, the clauses are usually joined by a coordinating conjunction. (Semicolons and dashes can also be used to join two independent clauses.) Knowing the seven coordinating conjunctions is crucial to mastering comma placement, as illustrated in this instructional video:

If your sentence starts with a short independent clause - fewer than five words - the comma is optional: I will stay and she will go home to watch TV.

Avoid using a comma to divide a compound verb phrase.

Don't confuse a compound verb ("We took . . . and visited. . . ".) with a compound sentence ("We took . . . and we regretted. . . ".) Look for two independent clauses that need separation and avoid adding the extra unneeded comma between compound verbs that share the same subject.

10.4 Use the "Oxford comma" to separate all the items in a series (including the penultimate item).

(Note: This is a guideline rather than a rule, but it's part of our management communication style guide.) When listing a series of items, include commas to separate all of the items.