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The majority of causes
of trouble in this world
are due to grammar
Michel de Montaigne
1533 - 92  French author

Cooperative learning series

Grammar: Commas & Modifiers

Grammar refers to the rules regarding the current standard of correctness in speech and writing. Advances in word processing software have included grammar-checking features.

Using Commas:; Do these sentences need commas?

My father went to the store for some dessert and bought ice cream.

No: Two verb phrases describing the action of the same subject do not need a comma if the conjunction separating them is "and."

My father went to the store for some dessert, bought ice cream, and came home in time to see his favorite TV show.

Yes: Three or more verb phrases describing the action of the same subject need commas to separate them.

The text Who Built America? describes reconstruction as a noble failure.

No: if Who Built America? was taken out of the sentence, when readers read "text," they would not know which text the writer means, so commas are not used when the title is in the sentence. (This is called a restrictive appositive.)


Practice using commas.;
Copy these sentences into word processing and insert commas where needed;
then read the explanations below.

  1. The restaurant dessert tray featured carrot cake coconut cream pie and something called death-by-chocolate.

  2. Because I was three hours short of graduation requirements
    I had to take a course during the summer.

  3. The weather according to last night's forecast will improve by Saturday.

  4. Students hurried to the campus store to buy their fall textbooks but several of the books were already out of stock.

  5. My sister asked "Are you going to be on the phone much longer?"


  1. The restaurant dessert tray featured carrot cake, coconut cream pie, and something called death-by-chocolate.
    The comma separates the items in a series.

  2. Because I was three hours short of graduation requirements, I had to take a course during the summer.
    The comma separates an introductory phrase or dependent clause from the rest of the sentence.

  3. The weather, according to last night's forecast, will improve by Saturday.
    The phrase "according to last night's forecast" interrupts the main clause, so it is set off by commas.

  4. Students hurried to the campus store to buy their fall textbooks, but several of the books were already out of stock.
    The comma separates an independent clause from a dependent clause.
  5. My sister asked, "Are you going to be on the phone much longer?"
    The comma separates a direct quotation from the rest of the sentence.

Misplaced/dangling modifiers

A modifier is a word or group of words;
that describes another word and makes its meaning more specific. Often modifying phrases add information about "where", "when", or "how" something is done. A modifier works best when it is right next to the word it modifies. For example, consider the modifiers in the following sentence (they are underlined for you):

The awesome dude rode a wave breaking on the shore.

The word "awesome" is an adjective (or, a one-word modifier);
it sits right next to the word "dude" it modifies.
The phrase "breaking on the shore" tells us where he rode the wave.
Thus, "breaking on the shore" is a modifying phrase
that must be placed next to the "wave" it modifies.

Below are some examples of poorly placed modifiers.
See if you can identify the problems:

Roger looked at twenty-five sofas shopping on Saturday.

Obviously twenty-five sofas were not shopping on Saturday. Because "shopping on Saturday" is meant to modify Roger, it should be right next to Roger, as follows:

Shopping on Saturday, Roger looked at twenty-five sofas.


The woman tore open the package she had just received with her fingernails.

Had the woman really received the package with her fingernails? The writer meant that she tore open the package with her fingernails.

With her fingernails, the woman tore open the package she had just received.


The waiter brought the pancakes to the table drenched in blueberry syrup.

What's drenched according to the sentence? The waiter, the table, or the pancakes?; Actually, the pancakes were drenched:

The waiter brought the pancakes, drenched in blueberry syrup, to the table.


Lying in a heap on the closet floor, Jean found her son's dirty laundry.

It sounds as if Jean was lying on the closet floor when she found her son's laundry!

Jean found her son's dirty laundry lying in a heap on the closet floor.



Vocabulary and spelling guides

Transitional words & phrases | More transitions | Transitional word game
Essay terms and directives | Modifiers & commas |
Spelling strategies | Spelling rules & exercises | Common misspelled words |
There - They're - Their | Too - Two - To | "Y" with suffixes |
Prefixes and root words | Suffixes and silent "e" |
Mapping vocabulary | Picturing vocabulary | American alphabet recited

This page modified thanks to Naoko Shibusawa, University of Hawaii and Susan Walter, University of Minnesota