Loyola University Chicago

Writing Center

5: Proofreading & Editing

After revising for content, unity, structure and coherence, you should read your paper carefully looking for errors in grammar, punctuation, sentence structure, spelling and word choice. Editing is sometimes necessary for clear communication and is always necessary to polish your work.

  • Get some distance on your writing by setting aside your revision for at least a couple of hours before proofreading; otherwise, you may read what is in your head rather than what is on paper.
  • Proofread slowly, perhaps moving a blank sheet of paper down each line to ensure that you look at details of each line of text.
  • Reading aloud helps you pay attention to each word.
  • Personalize proofreading by paying special attention to errors that you typically make, errors that your instructor has pointed out on previous papers; work with your instructor and a writing center tutor on strategies to correct errors that you tend to make.

Common Errors

Sentence Faults

Sentence faults include fragments and run-on sentences (fused sentences and comma splices).

Every sentence must include at least one independent clause, which is a group of words with a subject and a main verb (i.e., a verb that can change tense) and that is not a dependent or subordinate clause. If a sentence does not include an independent clause, it's a fragment.

Independent clause, a sentence: Sally jogs on the beach every day.

Dependent/subordinate clause, not a sentence: After Sally jogs on the beach every day.

The word "after" is a subordinate conjunction creating a subordinate clause that must be followed or preceded by an independent clause.

Sentence with a dependent and independent clause: After Sally jogs on the beach every day, she takes a nice hot shower.

Two independent clauses should be divided by more than a comma. If not, you have a run-on sentence.

Fused sentence, no punctuation between independent clauses: Joel studied very hard for his history test he passed with flying colors.

Comma splice: Joel studied very hard for his history test, he passed with flying colors.

Comma splicing is the most common sentence error students make. Various corrections are possible:

  • Make two sentences. Replace the comma with a period.
  • Replace the comma with a semicolon (;).
  • Add a coordinating conjunction: ...test, so he ...
  • Replace the comma with a semicolon and add a conjunctive adverb: ...test; therefore, he...
  • Make the first clause dependent: Because Joel studied very hard for his history test, he passed with flying colors.

Tangled Sentence Structures

Sometimes we begin a sentence with a structure that doesn't match the rest of the sentence; sometimes the parts of a sentence don't make sense together.

Example: By showing this contrast between the two versions of "Cinderella," it can show that how one behaves and conducts oneself around others is what is the most important thing.

Possible correction: Contrasting the two versions of "Cinderella" can show that a person's decent treatment of others is the most important theme of the story.

If you tend to make this kind of error, reading aloud is especially useful. Reading aloud is also useful for choppy sentences, wordiness and lack of parallel structure.

Choppy Sentences

Unless you've used short sentences for emphasis, look for ways to combine short, choppy sentences with coordination and subordination to show relationships between ideas.

Example: Victor Frankenstein is self absorbed. He does not realize it though. He just keeps going on with his life. He only sees his life as worthwhile. He puts his needs and fears above all others.

Possible correction: Because Victor Frankenstein is self absorbed, he goes through life putting his needs and fears above those of others.

Besides improving the flow of ideas, the revision cuts out unnecessary repetition.


Look for "dead wood" and cut it out of sentences.

Example: Throughout time there have been many different versions of "Cinderella" that have appeared on paper and have been read to children.

Possible correction: Throughout time, many versions of "Cinderella" have been read to children.

Lack of Parallel Structure

Check to be sure that items connected by words such "and," "or," "either...or," neither...nor," both...and," "not only...but also" are in the same grammatical form.

Example: Walt Disney's Cinderella is patient, hard working, and she takes care of the animals.

Possible correction: Walt Disney's Cinderella is patient, hard working, and nurturing.

Problems with Agreement

Subject/verb agreement: Check to make sure verbs agree with their subjects in number. Sometimes words come between the subject and verb, so be sure to identify the subject of the sentence.

Example: The flowers on the table are beautiful. (plural subject and verb)

Example: The vase of flowers is beautiful. (singular subject and verb)

Pronoun/antecedent agreement: The antecedent is the noun that the pronoun replaces; it must agree in number and person (gender).

Example: Students want to get A's on their tests.

Example: Sue studied for six hours for her history final exam.

Some nouns that sound plural are singular; especially look for words like "every," "everyone" and "each," which are singular.

Example: Everyone thinks that a suntan makes them look healthy. (everyone is singular; them is plural)

Possible correction: Most people think that a suntan makes them look healthy.

Problems with Pronoun Reference

Pronouns must replace specific nouns in a sentence; if you can't find a noun, insert one or replace the pronoun with a noun. Also avoid ambiguous references.

Example: Before Sue introduced Laurie, she shook hands with the guests.

Possible correction: Before introducing Laurie, Sue shook hands with the guests.

Other Problems with Verbs and Pronouns

Check to see if verb tense is consistent. Don't shift between present and past tense.

Check to see if you've used active rather than passive verbs, avoiding "to be" verbs as much as possible.

Example: The earth's environment is being threatened by global warming.

Possible correction: Global warming threatens the earth's environment.

Check to correct the indefinite use of the pronoun "you."

Example: In college, you should study three hours for each hour of class.

Possible correction: In college, students should study three hours for each hour of class.


Don't use a single comma between a subject and its verb.

Use a comma to separate two independent clauses that are joined by a coordinating conjunction (i.e., "and," "but," "for," "or," "nor," "yet" or "so"). Don't use a comma with these conjunctions if the two clauses are not independent.

Example: Kim woke up early, but she was still late for class.

Example: Kim woke up early but was still late for class.

Use a comma after elements coming before the independent clause. Check for subordinate conjunctions: "when," "although," "after," "until," "before" or "while."

Example: When Puck rolled over on her back, I leaned down to pet her.

Use a comma between all items in a series.

Example: Asters, lilies, and coneflowers grow easily in the Midwest.

Use two commas to set off non-restrictive elements. These are elements that are not essential to meaning. Restrictive elements should not be set off by commas.

Example: King Lear, Shakespeare's gloomiest tragedy, is rich and powerful.

Note that the phrase set off by commas can be removed.

Example: Shakespeare's tragedy King Lear is rich and powerful.

Note that "King Lear" cannot be removed from the sentence.

For more comma rules, see "Sentence Faults" above.

Other Punctuation

Semicolons (;)
Use a semicolon instead of a period between independent clauses that are closely related: IND;IND.

Example: Chicago's architecture is renowned; its parks and beaches are less well known.

Use a semicolon between independent clauses joined by a conjunctive adverb (e.g., "however," "moreover," "consequently," "therefore," "nevertheless," "furthermore" or "then").

Example: Joe ran ten laps; then he swam for an hour.

Use a semicolon between items in a series that contain commas.

Example: Mandy's favorite places to visit are Como, Italy; Burgundy, France; and San Sebastian, Spain.

Colons (:)
Use a colon after an independent clause that makes a generalization followed by detail(s) or explanation(s). IND: word, phrase, series expanding on generalization.

Example: Reba's favorite place to vacation is in southern France: Arles

Example: Tom likes a variety of cuisines: Mexican, Italian, Persian, and Thai.

Example: Vowing to bury her brother, Antigone shows courage: "I shall meet with nothing more grievous, at the worst, than death with honour" (4).

Don't use a colon before items in a series that are not introduced by an independent clause.

Apostrophes (')
Use an apostrophe to show possession.

Example: The computer's screen suddenly went blank.

Use an apostrophe for contractions.

Example: Students shouldn't stay up too late studying before an exam.

Don't confuse "its" and "it's."

Example: The cat is licking its paws. (possessive pronoun, no apostrophe)

Example: It's possible for students to enjoy themselves and still do very well in classes. (contraction meaning it is)

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