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Top 20 Errors in Undergraduate Writing

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The Top Twenty:
A Quick Guide to Troubleshooting Your Writing

Readers judge your writing by your control of certain conventions, which may change depending on your audience, purpose, and writing situation.  For example, your instructor may or may not mark errors in your paper if he’s more concerned with its argument or structure than he is with sentence-level correctness; he could also decide an error is not serious.  Some instructors may even see the errors listed below as stylistic options. However, a large-scale study by Andrea Lunsford and Karen Lunsford (2008) found that these errors are the most likely to attract readers’ negative attention.  Before handing in your papers, proofread them carefully for these errors, which are illustrated below in the sentences in italics.  


1. Wrong Word

Wrong word errors take a number of forms. They may convey a slightly different meaning than you intend (compose instead of comprise) or a completely wrong meaning (prevaricate instead of procrastinate). They may also be as simple as a wrong preposition or other type of wrong word in an idiom.

Use your thesaurus and spell checker with care. If you select a word from a thesaurus without knowing its precise meaning or allow a spell checker to correct spelling automatically, you may make wrong-word errors. If prepositions and idioms are tricky for you, look up the standard usage.

Here are a couple of wrong word examples:

Did you catch my illusion to the Bible?

Illusion means “an erroneous perception of reality.” In the context of this sentence, allusion was needed because it means "reference.”

Edmund Spenser’s The Faerie Queene is a magnificent sixteenth-century allergy.

A spell checker replaced allegory with allergy.

2. Missing Comma after an Introductory Element

Use a comma after every introductory element—whether word, phrase or clause—to clarify where it ends and the rest of the sentence begins. When the introductory element is very short, you can skip the comma, but including it is never wrong.

Without a comma after the introductory element, it’s hard to see the location of the subject (“they”) in this sentence:

Determined to make their flight on time they rose at dawn.

3. Incomplete or Missing Documentation

Documentation practices vary from discipline to discipline.  But in academic and research writing, it’s a good idea to always cite your sources: omitting documentation can result in charges of plagiarism.

The examples below follow MLA style.  In this example, the page number of the print source for this quotation must be included.

The Social Media Bible defines social media as the “activities, practices, and behaviors among communities of people who gather online to share information, knowledge, and opinions using conversational media.”

And here, the source mentioned should be identified because it makes a specific, arguable claim:

According to one source, it costs almost twice an employee’s salary to recruit and train a replacement. 

Cite each source you refer to in the text, following the guidelines of the documentation style you are using. 

4. Vague Pronoun Reference

A pronoun (e.g., he, this, it) should refer clearly to the noun it replaces (called the antecedent).  If more than one word could be the antecedent, or if no specific antecedent is present, edit to make the meaning clear.

In this sentence, it possibly refers to more than one word:

If you put this handout in your binder, it may remind you of important tutoring strategies.

In some pronoun usage, the reference is implied but not stated.  Here, for example, you might wonder what which refers to:

The authoritarian school changed its cell phone policy, which many students resisted.

To improve this sentence, the writer needs to make explicit what students resisted.

5. Spelling

Even though technology now reviews much of our spelling for us, one of the top 20 most common errors is a spelling error.  That’s because spell checkers cannot identify many misspellings, and are most likely to miss homonyms (e.g., presence/presents), compound words incorrectly spelled as separate words, and proper nouns, particularly names. After you run the spell checker, proofread carefully for errors such as these:

Vladmir Putin is the controversial leader of Russia.

Every where she walked, she was reminded of him.

6. Mechanical Error with a Quotation

When we quote other writers, we bring their voices into our arguments.  Quotation marks crucially show where their words end and our own begin. 

Quotation marks come in pairs; don’t forget to open and close your quotations.  In most documentation styles (e.g., MLA Style), block quotations do not need quotations marks.  Consult your professor’s preferred style manual to learn how to present block quotations. 

Follow conventions when using quotation marks with other punctuation. Here, the comma should be placed inside the quotation marks:

"A woman must have money and a room of her own if she is to write fiction", Virginia Woolf argues.

7. Unnecessary Comma

We often have a choice about whether or not to use a comma.  But if we add them to our sentences when and where they are not needed, then we may obscure rather than clarify our meaning.

Do not use commas to set off restrictive elements that are necessary to the meaning of the words they modify.  Here, for example, no comma is needed to set off the restrictive phrase of working parents, which is necessary to indicate which parents the sentence is talking about.

Many children, of working parents, walk home from school by themselves.

Do not use a comma before a coordinating conjunction (and, but, for, nor, or, so, yet) when the conjunction does not join parts of a compound sentence.  In this example, no comma is needed before the word and because it joins two phrases that modify the same verb, applies.

  This social scourge can be seen in urban centers, and in rural outposts.

Do not use a comma before the first or after the last item in a series.

The students asked their TAs to review, the assignment rubric, a sample paper and their comments, before the end of the quarter.

Do not use a comma between a subject and verb.

Happily, the waiters, sat down during a break.

Do not use a comma between a verb and its object or complement.

On her way home from work, she bought, a book at the bookstore.

Do not use a comma between a preposition and its object.

On her way home from work, she bought a book at, the bookstore.

8. Unnecessary or Missing Capitalization

Capitalize proper nouns and proper adjectives, the first words of sentences, and important words in titles, along with certain words indicating directions and family relationships. Do not capitalize most other words. When in doubt, check a dictionary.

Financial Aid is a pressing concern for many University Students.

9. Missing Word

If you read your work outloud before submittingit, you are more likely to notice omitted words.  Be particularly careful not to omit words from quotations.

Soccer fans the globe rejoiced when the striker scored the second goal.

10. Faulty Sentence Structure

If a sentence starts out with one kind of structure and then changes to another kind, it will confuse readers.

The information that families have access to is what financial aid is available and thinking about the classes available, and how to register.

Maintain the grammatical pattern within a sentence.  Each sentence must have a subject and a verb, and the subjects and predicates must make sense together.  In the example above, thinking about the classes available does not help the reader understand the information families have access to.  Parallel structures can help your reader see the relationships among your ideas.  Here’s the sentence revised:

Families have access to information about financial aid, class availability, and registration.

11. Missing Comma with a Nonrestrictive Element

A nonrestrictive phrase or clause provides additional information that is not essential to the basic meaning of the sentence.  Use commas to set off a nonrestrictive element.

David who loved to read history was the first to head to the British Library.

The clause who loved to read historydoes not affect the basic meaning of the sentence.  The clause could be taken out and the reader would still understand that David was the first to head to the British Library.  

12. Unnecessary Shift in Verb Tense

Verbs that shift from one tense to another with no clear reason can confuse readers.

Martin searched for a great horned owl.  He takes photographs of all the birds he sights.

13. Missing Comma in a Compound Sentence

A compound sentence consists of two or more independent clauses.  When the clauses are joined by a coordinating conjunction (for, and, nor, but, or, yet, so), use a comma before the conjunction to indicate a pause between the two thoughts.

Miranda drove her brother and her mother waited at home.

Without the comma, a reader may think at first that Miranda drove both her brother and her mother.

14. Unnecessary or Missing Apostrophe (including its/it's)

To make a noun possessive, add either an apostrophe and an s (Ed's phone) or an apostrophe alone (the girls’ bathroom). Do not use an apostrophe in the possessive pronouns ours, yours, and hers. Use its to mean belong to it; use it's only when you mean it is or it has.

Repeated viral infections compromise doctors immune systems.

The chef lifted the skillet off it’s hook.  Its a fourteen-inch, copper skillet.

15. Fused (run-on) Sentence

A fused sentence (also called a run-on) joins clauses that could each stand alone as a sentence with no punctuation or words to link them. Fused sentences must be either divided into separate sentences or joined by adding words or punctuation.

The house was flooded with light, the moon rose above the horizon.

He wondered what the decision meant he thought about it all night.

16. Comma Splice

A comma splice occurs when only a comma separates clauses that could each stand alone as a sentence. To correct a comma splice, you can insert a semicolon or period, connect the clauses with a word such as and/or/because, or restructure the sentence.

The students rushed the field, they tore down the goalposts. 

17. Lack of pronoun/antecedent agreement

Pronouns typically must agree with their antecedents in gender (male or female, if appropriate) and in number (singular or plural). Many indefinite pronouns, such as everyone and each, are always singular.  However, theycan be used to agree with a singular antecedent in order to use inclusive or gender-neutral language.  When antecedents are joined by or or nor, the pronoun must agree with the closer antecedent. A collection noun such as team can be either singular or plural, depending on whether the members are seen as a group or individuals.

Every guest left their shoes at the door.

18. Poorly Integrated Quotation

Quotations should be logically and smoothly integrated with the writing around them, the grammar of the quotation complementing the grammar of the neighboring prose.  They usually need to be introduced (with a signal phrase) rather than dropped abruptly into the writing.

An award-winning 2009 study of friendship "understanding social networks allows us to understand how indeed, in the case of humans, the whole comes to be greater than the sum of its parts" (Christakis and Fowler 26).

"Social networks are intricate things of beauty" (Christakis and Fowler xiii). Maintaining close friendships is good for your health.

19. Missing or Unnecessary Hyphen

A compound adjective requires a hyphen when it modifies a noun that follows it.

This article describes eighteenth century theater.

A two-word verb should not be hyphenated. 

The dealers want to buy-back the computers and refurbish them.

20. Sentence Fragment

A sentence fragment is part of a sentence that is presented as if it were a complete sentence.  The following illustrate the ways sentence fragments can be created:

Without a subject

The American colonists resisted British taxation.  And started the American Revolution.

No complete verb

The pink geranium blooming in its pot.

Beginning with a subordinating word

We visited the park. Where we threw the Frisbee.


These 20 most common errors can be avoided in your writing if you reserve time to proofread your final draft before submission.

Works Cited

Lunsford, Andrea A. and Karen J. Lunsford.  “Mistakes are a Fact of Life: A National Comparative Study.”  CCC 59 (2008) 781-806.