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Grammar: Punctuation

Tips to help students improve their grammar skills

Why Punctuation Is Important

without punctuation sentences become difficult to read it is hard to figure out where pauses should go organization becomes harder correct punctuation guides readers through the maze of each sentence showing them where to pause and where to stop punctuation separates ideas while this may be an extreme example punctuation is essential for the readability of any text

misused Punctuation, is just as Difficult; to/understand. the "meaning" of the writers Word's--as no puncuation? Is therefore [be sure] to use the correct! Punctuation "mark": at the, correct (Time)

Ellipses . . .

Ellipses are written: word, space, dot, space, dot, space, dot.  They never have more than three dots.  They never have less than three dots.  They are used to show that something from a quote has been omited, or in dialogue, they show that the speaker has trailed off while speaking, without finishing his or her sentence.

When using ellipses to shorten a long quote, be careful not to change the meaning of the quote.  For example: The seventh commandmant says, "Do . . . commit adultery."  This would be an obvious instance of changing the meaning of a quoted passage by using an ellipse.  You also need to be careful that you don't accidentally change the meaning in a more subtle way.

End Punctuation . ? !

End punctuation goes--surprisingly--at the end of sentences.

The period is the most used end punctuation, especially in academic writing.  

Should you use question marks at the end of questions? Yes.

Use exclamation marks at the end of sentences to show extreme emotion.  Yes!  This is so right!  However, be careful not to overuse the exclamation mark.  In non formal writing, its overuse will actually weaken your points, and in formal writing you should almost never use it.

Hyphens and Dashes - --

The hyphen is located after the 0 in the number's row on your keyboard.  

Use hyphens between words that are functioning as a single word.  Here are some examples:

a three-year-old


Also, words forming adjectives before a noun are hyphenated, but ones after a noun are not.

Example: A well-known actor is performing tonight.  The actor is well known.

Example:  The tick-infested dog growled menacingly.  The growling dog was tick infested.


Dashes are made by typing two hyphens.  Your computer will probably autoformat that to form a longer dash.  Dashes are used to mark a break in the normal progression of a sentence--placing more importance on the information that follows it.



Parentheses go around an aside or comment that is not integral to the meaning of the sentence (like this one -- this sentence would make just as much sense if everything in the parentheses was taken out). 


Italics are used for emphasis, although you should typically avoid using them in academic papers as they are generally considered informal. Italics are also used for the titles of books, movies, magazines, and plays. 

Example: Star Wars is my favorite film series -- I've seen each movie 27 times and I'm still not tired of them. 


The marks used in writing to separate sentences and clarify ideas.


Correct Usage

1.  Joining sentences with a conjunction.

(sentence that could stand alone) + COMMA + conjunction + (sentence that could stand alone).

I am a nice person, because I drink detox tea every morning.

I am a nice person (could stand alone), because (conjunction) I drink detox tea every morning (could stand alone).

2.  After introductions

(Introductory word or words) + COMMA + (sentence that could stand alone)

Usually, I wake up at 5:00 in the morning.

Usually (introduction), I wake up at 5:00 in the morning (sentence that could stand alone).

Thinking it was an hour later, I got up at 4:00 this morning.

Thinking it was an hour later (introduction), I got up at 4:00 this morning (sentence that could stand alone).

3.  Separating things in a list.

Eating breakfast, drinking tea, and brushing my teeth are the three things I do every morning.

I take a walk past the dark, forboding forest every day.

4.  Setting off nonessential pieces of information

Lydia, my silly sister, made a cross-eyed face at my nephew.

"My silly sister" does not change the meaning of the sentence.  It adds information, but the sentence would mean basically the same thing without it.  Therefore, it is set off with commas.

The Five Iron Frenzy concert, which was near where my brother lived, was going to be in March.

"Which was near where my brother lived" adds information, but it doesn't change the meaning of the sentence.  Therefore, it is set off with commas.

If there were many Five Iron Frenzy concerts, and I was clarifying which one was in March, I would write, "The Five Iron Frenzy concert that was near where my brother lived was going to be in March."  Now "that was near where my brother lived" is an essential part of the sentence, because it distinguishes this one from other ones.

5.  With place names

Winona Lake, Indiana, is a lovely place to live.

(city) + COMMA + (state) + COMMA + (the rest of the sentence).

6.  With the date

I came home on Friday, March 21, 2007, to find that my parents had moved.

7.  Before quotations

He said, "I love you."

Common Errors

1. The Comma Splice

This is when you try to connect two otherwise complete sentences with just a comma.

The cow was pulled over for drunk driving, his license was suspended.  Since both of these sentences could stand on their own, there needs to be more than just a comma connecting them.  Possible fixes:

The cow was pulled over for drunk driving, and his license was suspended.

The cow was pulled over for drunk driving.  His license was suspended.

The cow was pulled over for drunk driving; his license was suspended.

The cow was pulled over for drunk driving--his license was suspended.

2.  Splitting Up the Subject and Verb

3.  Splitting Up the Verb and its Object

4.  Following a Conjunction

Apostrophes '

Apostrophes are used to show possession.

That is Jim's helmet; the helmet belongs to Jim.

Apostrophes are also used to indicate a missing letter in a contraction.

Don't sit there!  That's where he is going to sit.

You should not use contractions in formal writing.

Apostrophes are not needed in the following words, unless they are being used to show possession:

The 1980s

The ABCs

The Smiths

The Blacks


Brackets can be used in the middle of a section of quoted material to indicate that the content in the brackets is your own words, and not part of the quote.  Use this to clarify something that the text says.

Example: "The rich young ruler asked him [Jesus] 'What must I do to be saved?'" 


Colons are used to introduce lists of items in a sentence, if the list is preceded by an independent clause. 

Incorrect: Sebastian brought three things to the picnic and they were: food, a basket, and his cat. 

Correct: Sebastian brought three things to the picnic: food, a basket, and his cat. 

Colons are also used after introductory phrases that can stand on their own. 

Incorrect: Charlotte told me today that: she is moving to Cleveland. 

Correct: Charlotte told me something unexpected today: she is moving to Cleveland. 

Numbers 123

Depending on what style you are using, the rules for numbers will be different.

MLA says to spell out numbers that can be expressed in on or two words, and use the numerals for all other numbers.  In his collection were nine hedgehogs, one hundred fire hydrants and three fourths of an elephant.  But there used to be 543 llamas, 4.8 hurricanes and 34.352 sea shells.

APA says to spell out numbers below ten and common fractions.  Also, it is acceptable to spell out numbers when the common usage is to spell them out, for example, the Twelve Apostles.  In his collection were nine hedgehogs, 100 fire hydrants and three fourths of an elephant.  But there used to be 543 llamas, 4.8 hurricanes and 34.352 sea shells.

Both styles suggest spelling out the number if it begins a sentence (or rewording the sentence so that you do not have to spell out longer numbers).

Numerals should be used for years, in addresses, for identification, for page numbers, for decimals and percentages, for large fractional numbers and for expressing monetary amounts.

Subject Guide

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Semicolons are used to connect what could be two complete sentences that are closely related to each other.

Example: "It's a lovely day; let's go for a walk!"

Slashes /

Slashes are not usually used in formal writing, but informally, you can use them when one of two words could fit in a sentence. 

Example: You can study in the library and/or outside. 

Slashes also indicate line breaks in poems or songs. 

Example: "Hope is the thing with feathers - / That perches in the soul - / And sings the tune without the words -"


Words at the beginning of a sentence should be capitalized.  Proper nouns (names of people, places, companies, etc) should be capitalized.

Be careful not to over-capitalize words.  Here are a few examples of capitalizing too much:

Incorrect: His Mom made us sandwiches.  If you use "mom" as her name, it is capitalized, but here it is just being used to show her relationship to him.

Correct: His mom made us sandwiches.  He said, "Thanks, Mom!"  "Mom" is capitalized when used as a name, but not when used otherwise.

Incorrect: I enjoyed my years in Middle School.  Here "middle school: is not referring to a particular school, so it should not be capitalized.

Correct: I enjoyed my years in Washington Middle School, even though I know a lot of people who do not enjoy middle school.

Incorrect: I took a Speech Class as part of the General Education requirements at my College.

Correct:  I took a speech class called Public Speaking as part of the general education requirements at my college.

"Quotation Marks"

Names of Short Works

Double quotation marks should be placed around the names of short works, such as short stories, essays, articles, book chapters, short poems, songs, and TV episodes.  Longer works should be placed in italics.

Exact Words of an Author

In academic writing, you will frequently need to quote sources to support the main points of your essay.  When you quote these works, the exact words of the author should appear in double quotation marks.  For more on quoting, see libguides page "Quoting."

Spoken Words of a Character

Most common in fiction writing, the spoken words of a character should be placed in double quotation marks.

Direct Thoughts of a Character

The direct thoughts of a character should also be in double quotation marks.

Words Used in an Unusual Manner

Sometimes quotation marks are put around words that are not being used according to their dictionary definition.  For example: He was a very "nice" man; he assassinated his targets quickly instead of making them suffer.  In academic writing, however, this usage of quotation marks should be avoided.  Also avoid using quotation marks around unacademic words--that is like apologizing for your poor word choice.  Don't apologize; make it better!