Using Commas (and other punctuation) Correctly 1
One common area where students seem to struggle is with comma usage. Have you ever said this: I
think I should put a comma here, but Iām not sure. Is there a rule for this?
Carrell, Wilson, and Forlini (2004) stated that there are two basic uses for commas: ā(1) Commas can be
used to separate similar items and (2) one or more commas can be used to set off a single item at the beginning,
middle, or end of a sentence. Do not use a comma unless there is a comma rule for itā (p. 658). Here are the
comma rules that they include in their grammar text:
1. Commas with compound sentences
A compound sentence contains two or more independent clauses joined by a conjunction (and, but, for,
nor, or, so, and yet). A comma is placed after the first independent clause and before the conjunction.
An independent clause can stand on its own as a complete sentence; it contains a subject and a verb.
The dance was advertised as an informal affair, but most of the students dressed in their Sunday
best.
Note that no comma is needed in the following sentence: āMuch food is put through a process called
irradiation so that most of the bacteria on the food is killed by radiationā (p. 659). The part of the
sentence following the word āsoā is not an independent clause. If you removed the word āthatā, it would
be a compound sentence.
NOTE: If you have two independent clauses in a sentence that are not separated by a
conjunction, a semicolon should be inserted after the first clause.
The students in the first seven rows were in the baccalaureate program; those in the last
three rows were in the masterās program.
ALSO: When two independent clauses are separated by a conjunctive adverb (however,
furthermore, nevertheless, etc.) a semicolon precedes the conjunctive adverb and a comma follows it.
The dance was advertised as an informal affair; nevertheless, most of the students dressed in
their Sunday best.
2. Commas between items in a series
A series is a string of āthree or more similar items. These items may be words, phrases, or clauses [and]
must be separated by commasā (p. 660). As a rule of thumb, you will have one fewer comma than the
number of items in the list. You should insert a comma before the conjunction.
The studentās study objectives were to read the chapter, to complete the practice problems, and
to review the notes from the previous lecture.
The items in the series should be parallel in structure, so that if each item is placed in the sentence by
itself, it will make sense:
The studentās study objective was to read the chapter.
The studentās study objective was to complete the practice problems.
The studentās study objective was to review the notes from the previous lecture.
Exceptions:
a.āWhen each item in the series is joined to the next item by a conjunction, no
commas are necessaryā
Super markets and grocery stores and restaurants all sell a variety of foods to consumers
(p. 660).
