Grammar and Punctuation Tips

 Prepared by Jill Cienki, December 2003

As a tutor in the Writing Center, I have observed a number of common grammar and punctuation mistakes that writers frequently make. The following tips focus on the common errors that I have seen students make in their papers. This reference sheet is not a review of all the necessary grammar and punctuation rules; rather, it is an overview to help students troubleshoot common errors.


When to Use Commas

1.     Use a comma to separate an introductory phrase from the rest of the sentence. In other words, if there is a group of words at the beginning of the sentence that seems to be introducing more information, set it off with commas to make it clearer. Placing a comma after introductory phrases signals to the readers that they are about to learn more about the subject. Hereís an example:

After Sarah and Janna went ice skating, they went to the mall.

If you read the sentence aloud, you can sometimes hear that a phrase is acting like an introduction. If it is, follow it up with a comma.

2.     Use commas between all items in a series, including before the coordinating conjunction.

For Thanksgiving, Allisonís grandmother made turkey, sweet potatoes, green beans, and apple pie.

Many students feel that the comma before the coordinating conjunction is not needed, but it is.

3.     Use a comma before the word which in a sentence. Descriptive information introduced by the word which is not considered essential to the meaning of the sentence, and it is set off with commas.

Devonís garden, which is full of flowers, is located on the side of her house.

The fact that the garden is full of flowers is a nice description, but it has nothing to do with the fact that it is located on the side of her house.

4.     When writing an address, most students remember to place a comma between the city and the state or country, but many students do not realize that a comma is also needed after the state or country.

Justin Williams was born in Cobourg, Ontario, on October 4, 1981.

Donít forget that a comma is also needed between the day and the year in a date.

5.     Never separate the subject of a sentence from its verb with a comma.

Wrong: Many fans who attend football games, bring blankets and radios.

Correct: Many fans who attend football games bring blankets and radios.

6.     Use a comma before a coordinating conjunction that joins two sentences. Do not place a comma after the conjunction.

Wrong: Keith likes the color orange but he doesnít like oranges.

Also Wrong: Keith likes the color orange but, he doesnít like oranges.

Correct: Keith likes the color orange, but he doesnít like oranges.

If you do not use a comma in the example above, then the sentence is a run-on.

Still have questions about commas? Then check out the following web sites for even more examples and help.

        Temple University Writing Center:

        Bowling Green State University Writing Lab Online:

The Hyphen

Using hyphens isnít difficult, but it is important to know when they are necessary. I am often asked whether a hyphen is needed between the italicized words in the following sentence:

Susan is a well known poet.

The way to go about this sentence is to look at how the words well and known are working in the sentence. Here, they are both describing the noun poet. Because they are describing a noun, they are acting as adjectives. A hyphen is needed, and the sentence should read:

Susan is a well-known poet.

However, a hyphen is not needed in the following sentence:

Susan is well known.

Why no hyphen? The words well and known do not come before a noun.

Still confused about hyphens? Look up the word or words in question in a dictionary. Dictionaries will usually tell you what to do with a compound word.


Avoiding Run-On Sentences

Run-on sentences occur often but are easy to fix. Hereís an example sentence:

Andrew is a very anxious man he is always worrying.

This is a run-on sentence because there are two smaller sentences improperly joined together. There are four main ways to fix a run-on sentence.

1.     Insert a comma and a coordinating conjunction.

There are seven coordinating conjunctions in English: and, but, or, for, nor, yet, so. Thatís it. You can add a comma followed by a coordinating conjunction to fix the sentence:

Andrew is a very anxious man, and he is always worrying.

***Ever wonder what a comma splice is? Well, a comma splice occurs when a writer joins two smaller sentences (independent clauses) with a comma but leaves out the coordinating conjunction. Remember, both a comma and a coordinating conjunction are needed; otherwise, the sentence is still a run-on.

2.     Insert a semicolon.

A semicolon can be used to join the two fused sentences. This works best if the two smaller sentences are related to one another in some way. In the example sentence, the fact that he is always worrying describes Andrew and the fact that he is anxious.

Andrew is a very anxious man; he is always worrying.

3.     Divide the run-on into two smaller sentences.

There is nothing wrong with dividing a run-on sentence into smaller sentences. But it is important to use other ways to fix run-on sentences as well, or your paper may end up with many short sentences. Having too many short sentences is stylistically awkward.

Andrew is a very anxious man. He is always worrying.

4.     Rewrite the sentence. This takes more work than changing the punctuation of the run-on sentence, but it is usually worth the effort.

Andrew, a very anxious man, is always worrying.


Punctuation Around Quotation Marks

It is generally understood that quotation marks are used to enclose direct quotations; however, it is common for writers to misplace the punctuation around quotation marks. Here are a few reminders:

1.     Commas and periods go inside the quotation marks (except in the case of parenthetical citation).

"This box is too heavy," Anna said. "I think I might drop it."

The Exception: When citing a quotation from a book with parenthetical citation, the period goes outside the parentheses.

Anna said, "This box is too heavy" (Smith 8).

2.     Question marks and exclamation points go inside the quotation marks.

Anna asked, "Is this box too heavy?"

The Exception: When citing a quotation that has a question mark or exclamation point, the punctuation goes inside the quotation marks, and the citation is followed by a period of its own.

Anna asked, "Is this box too heavy?" (Smith 8).

3.     Colons and semicolons go outside the quotation marks.

Anna said, "This box is too heavy"; the box, however, had nothing in it.


More about Quotation Marks

Quotation marks can be used to do things other than setting off direct quotations. Here are some ways that students tend to get tripped up with quotation marks:

1.     Use quotation marks when using a word as a word.

The word "posh" has an interesting word history.

Words used in this way can also be italicized or underlined.

2.     Use quotation marks for the titles of short works such as newspaper articles, short poems, short stories, essays, songs, or chapters of a book.

Stephen Craneís short story "The Open Boat" is widely read in high schools.

3.     Do not use quotation marks around indirect quotations. In other words, quotation marks are not needed if you are using your own words to tell the reader what another person said. Hereís an example:

Samantha said that "she would be late to class today."

The quotation marks in the above sentence are not needed because you are not directly quoting Samantha; you are paraphrasing what she told you. The sentence should read:

Samantha said that she would be late to class today.

4.     Do not use quotation marks around familiar words or sayings in order to draw attention to them. The quotation marks in the following sentence are not needed:

Most of the students in the class believe that Anthony is a "teacherís pet."

Students usually use quotation marks here because they want to draw attention to a phrase or to emphasize an important point; however, the quotation marks are not needed to create this emphasis.

5.     Do not use quotation marks around an indented quotation. The fact that the text is indented lets the reader know that it has been quoted. When should you indent a quotation? Indent a quotation when quoting more than four lines of prose or more than three lines of poetry. Here are a few examples of indented quotations:

Prose Quotation:

Raphael disagreed with Thomas Moreís vision of a utopian society:

In other words, I am quite convinced that youíll never get a fair distribution of goods, or a satisfactory organization of human life, until you abolish private property altogether. So long as it exists, the vast majority of the human race, and the vastly superior part of it, will go on labouring under a burden of poverty, hardship, and worry. (More 66)[1]

(Notice that the parenthetical citation is placed outside of the punctuation. This is because it applies to the entire indented quotation.)



Poetic Quotation:

The description of Beowulfís defeat of the monster Grendel is wonderfully graphic:

. . . The monsterís whole

body was in pain, a tremendous wound

appeared on his shoulder. Sinews split

and the bone-lappings burst. Beowulf was granted

the glory of winning; Grendel was driven

under the fen-banks, fatally hurt,

to his desolate lair . . . . (Beowulf 55)[2]

(Again, the parenthetical citation is placed outside of the punctuation.)


Underlining and Italics

If you understand when to use quotation marks, then it is easy to remember when to use underlining or italics. As a general rule, italics and underlining are interchangeable, and it is always a good idea to find out if your professor has a preference.

1.     Titles of large works underlined or italicized: newspapers, books, magazines, pamphlets, long poems, plays, films, television programs, and web sites.

The New York Times is one of the most widely read newspapers in the United States.

2.     Foreign words or phrases in an English sentence are underlined or italicized.

Many politicians advocate a laissez faire approach to economics and business.



Who vs. Whom

One way to decide whether to use who or whom in a sentence is to look at the sentence in parts. Look at the following sentence in two parts:

Sarah is the girl who/whom bought the red bicycle.

The first part of the sentence can be considered the main part of the sentence. Everything after it works grammatically by itself. By itself, the second part of the sentence looks like a mini sentence of its own. Now, in order to decide between who and whom, look at how the word is operating in the sentence. It is the subject of the verb bought. Because it is the subject, you should use the subjective word who. Another way to remember this is to use another pronoun in the second part of the sentence as a test like this:

She bought the red bicycle. Her bought the red bicycle.

She is also a subject pronoun and is the correct choice.


Hereís another sentence:

The girl who/whom I saw on television was at the mall.

This one is a little tricky. Again, break the sentence into two parts. The girl was at the mall is the main sentence. Who/whom I saw on television is a phrase that describes the girl. Now, concentrate on the grammar of the part in question. The subject is I and the verb is saw. Just ask yourself the question: I saw what? The answer is I saw who/whom. In this part of the sentence, the word in question comes after the verb saw, and it is a direct object. This means that the word should be in objective case, and the objective case word is whom.


Its vs. Itís

The word itís is a contraction. If the contraction is broken down, the word itís is really saying it is. Because it is a contraction, an apostrophe is needed.

Itís really cold outside. (Same as: It is really cold outside.)

The word its is a possessive pronoun but does not need an apostrophe. Confused? Think of the possessive pronouns hers, yours, and theirs. They donít need apostrophes either.

The cat picked up its toy mouse and walked out of the room.


Which, That, or Who

Sometimes it is hard to remember when it is appropriate to use the words which, that, and who. Here are a few tips to help you remember when and how to use these words:

1.     Use the word who only when referring to individual people.

Jeff is the student who always comes to class late.

2.     Use the word that when referring to a group of people.

The marching band that won the competition had five tuba players.

3.     The word that can also be used to introduce descriptive information that is essential to the meaning of the sentence. In other words, if you cannot understand the meaning of the sentence without the descriptive information, introduce it with that.

Mark is a player on the team that won the game.

Without the descriptive information that won the game, the reader would be left to wonder what team Mark played for.

4.     Use the word which to introduce descriptive information that is not essential to the meaning of the sentence. In other words, if you can understand the sentence without the descriptive information, introduce it with which. (Never use the word which to refer to people or groups of people.)

The student needed a good grade on his history test, which was very difficult.

The fact that the test was difficult describes the test but is not important to the meaning of the sentence. It is an extra detail, so it is introduced by which. Also, when the word which is used, it is preceded by a comma; this signals to the reader that the description is just extra information.


When writing these grammar and punctuation tips, I relied upon my understanding of English grammar and punctuation as well as Diana Hackerís A Writerís Reference. For more information on these and other common problems that writers face, check out the following helpful web sites:

        Temple University Writing Center:

        Bowling Green State University Writing Lab Online:

        Purdue University Online Writing Lab:


Written By: Jill Cienki

December 10, 2003