How to Read for Punctuation and Grammar Mistakes

Watch out for apostrophes. Many people accidentally misuse apostrophes in their writing. Each time you see an apostrophe used, take a moment to make sure it's used correctly.

• Apostrophes are used to show possession. To show something belongs to someone, you would use an apostrophe and then an "s" or an apostrophe after an "s." An apostrophe and then an "s" is used for singular nouns, indefinite pronouns (anybody, somebody, etc.), and plural nouns that do not end in "s" (fish, deer, etc.). An apostrophe following an s is only used for plural pronouns that end in an "s."^[7]
• For example, "I asked if I could pet the man's dog." As "man" is a singular noun, the apostrophe comes before the "s." In the sentence, "All the students' papers were turned in late," the apostrophe comes after the "s" as students is plural and ends in "s."
• The word "it" is an exception. If it is possessive, it's spelled "its." The construction "it's" is a contraction, meaning "it is." For example, "The dog is chewing on its toy. It's a black Labrador."^[8]

Make sure colons and semi-colons are used correctly. Semi-colons and colons are often used incorrectly or used in place of one another. Each time you see one of the two used, pause to make sure the usage is correct.

• Semi-colons are usually used to connect closely related ideas when a comma is not appropriate. Semi-colons can link independent clauses, clauses connected by transitional phrases or conjunctive adverbs, or lengthy clauses with multiple commas in each clause to avoid confusion. Usually, semi-colons should be used between two clauses that could stand on their own independently.^[9]
• A common error regarding semi-colons is using a comma when a semi-colon would be appropriate. For example, "The dog is big, it is also brown." As there is no conjunction connecting those two clauses, and the ideas are connected, a semi-colon would be more effective here. "The dog is big; it is also brown."^[10]
• Another common error regarding semi-colons is using one in place of a colon. A colon is used to say, "that is to say" or "here is what I mean." It's most commonly used before lists in a sentence. For example, "Jane went to the store and bought everything she needed for the cookies: spices, sugar, flour, and icing."^[11]
• A colon can also be used much the same way a semi-colon is used, to connect two clauses, but only if specific requirements are met. A colon should only be used in place of a semi-colon if the second clause explains the first. For example, "Mark's long career in law paid off: he was elected district judge that year." As the second clause explains what the first was alluding to, Mark's election as judge being what his law career lead to, a colon is appropriate.
• Two ideas that are merely connected would still require a semi-colon. For example, "Mark got to the courthouse at noon; he put on his judge's robes." As the robes do not offer an explanation for the first clause, a semi-colon is used.^[12]

Fix comma splices. Commas are one of the most misused forms of punctuation. While proofreading a paper, watch out for comma splices.

• Read through your paper and take note of every use of a comma. For example, take the sentence, "Eve went to the drugstore, she picked up a prescription for painkillers." Read the first part of the sentence. Does it make sense on its own? Yes. Read the second part. That also makes sense on its own. This is a comma splice and the error should be corrected.
• There are three ways to fix a comma splice. You could add a conjunction that merges the sentences together. For example, "Eve went to the drugstore and picked up a prescription for painkillers" or "Eve went to the drugstore to pick up a prescription for painkillers."
• Second, you could replace the comma with a period and make two sentences. "Eve went to the drugstore. She picked up a prescription for painkillers."
• Third, you could replace the comma with a semicolon if the sentences are closely related. "Eve went to the drugstore; she picked up a prescription for painkillers."

Watch for sentence fragments. A sentence fragment is a statement with a period, question mark, or some form of punctuation that fails to stand on its own as a sentence.

• Fragments are most often a piece of a sentence disconnected from a main clause. For example, "My old roommate never paid rent on time. Which is why I need a new roommate." The second part of that thought is a sentence fragment. It can be corrected by merging the two. "My old roommate never paid rent on time, which is why I need a new roommate."^[13]
• Sentence fragments can also be a sentence without a main verb. For example, "A book with a morally ambiguous main character." This tells about the book and its characters, but there's no action happening which means it is not a full sentence. A possible revision would be, "This book features a morally ambiguous main character" the verb becoming "features."^[14]
• Sometimes, sentence fragments lack a subject. For example, "With the intended effect of the law being deterring drunk driving in the city." The subject is unclear. A revision might be, "The law's intended effect is deterring drunk driving in the city."^[15]

Break down run-on sentences. Run-on sentences can be somewhat difficult to detect as they can sometimes appear grammatically correct if not read closely. Run-on sentences are very long sentences when two or more clauses are joined without the use of a comma, semi-colon, conjunction, or other means of connecting sentences.^[16]

• A good way to detect run-on sentences is to read a work out loud. Listen to your own voice. If you find the sentence difficult to finish in a single breath, and if you find it's hard to follow when spoken out loud, it might be a run-on sentence.
• A run-on sentence can usually be corrected through the use of a comma, semi-colon, or other device to unite the two sentences. For example, "My favorite movie is It's A Wonderful Life it is a very heartwarming Christmas story." This is a run-on sentence as the two clauses ("My favorite movie...", "it is a...") are not properly connected. It could be fixed in a number of ways.
• You could break down the run-on into two sentences. "My favorite movie is It's A Wonderful Life. It is a very heartwarming Christmas story." You could use a semi-colon, as the ideas are connected. "My favorite movie is It's A Wonderful Life; it's a very heart warning Christmas movie." You could also use a conjunction to unite the clauses. "My favorite movie is It's A Wonderful Life because it's a heartwarming Christmas story."

Watch for sentence sprawls. Sentence sprawls are very long sentences that, while usually technically grammatically correct, can be difficult to read. Some writers use sentence sprawls stylistically, but unless a sentence sprawl is intentional and meant to convey something to the reader you should minimize their use. In general, if you notice a very long sentence that takes up more than two lines, try to break it up into multiple sentences.^[17]

Make sure the subject and verb of each clause agree. Subject/verb agreement means singular subjects have singular verbs, and plural subjects have plural verbs. People sometimes make mistakes with S/V agreement when writing sentences with multiple clauses or longer sentences as they lose track of what the subject was.

• In some sentences, the subject appears before another noun and you may accidentally have the verb agree with the second noun over the actual subject. For example, take the sentence "The profits brought in by the bar industry is off this season." At first glance, this may appear correct as "is" comes after "bar industry." However, the subject of the sentence is "the profits," not the bar. Therefore, the correct construction would be "The profits brought in by the bar industry are off this season."^[18]
• When joining two singular subjects with a conjunction like "and", the verb should be plural even though the subjects themselves are singular. For example, "Mary and her friend takes the train into the city each day" is incorrect as both "Mary" and "her friend" are singular nouns, but they are presented as a plural unit. The correct construction would be "Mary and her friend take the train into the city each day."^[19]

Keep the same verb tense throughout the sentence or passage. Shifting between present and past tense may confuse the reader. Make sure your verb tense is always in agreement.

• People often slip up by mistake with tense agreement, especially when typing quickly. Past and present tense verbs are often spelled in similar ways, leading you to make an error. For exampled, "James entered the room and sit down on the chair." As "sit" and "sat" differ only by one letter, this is an easy mistake to make. The sentence should be, "James entered the room and sat down on the chair."

Watch for basic spelling errors and typos. Even people generally good with spelling and grammar occasionally make mistakes.

• Dropped words are a common typo. You may forget the "is" or "the" in a sentence if you worked too quickly. Reading a work out loud can help you catch dropped words.
• Do not rely solely on spellcheck. Spellcheck can be a helpful feature but it does not catch all spelling and grammar errors. If, for example, you typed "quite" instead of "quiet" spellcheck would not catch this error.
• Know what words you tend to misspell. Words like "unnecessary," for example, can trip people because of the multiple letters. Keep a running list of words you frequently stumble over and pay attention to their use in your paper.

Watch for passive voice. Using passive voice is generally advised against unless you work in a few specific disciplines. Watch for the passive voice as you edit your work.

• The subject of a sentence should be the person, place, or thing doing the action. This is called the active voice and you should generally use the active when writing.
• In the passive voice, some form of the verb "to be" (e.g., is, are, was, were) is used with a past participle (a verb in the past tense). This can be needlessly confusing to read and takes attention away from the action, which should be the primary focus of a sentence.
• For example, take the sentence "The dog was walked by Holly." This sentence is in the passive voice. To correct it, you would change it to, "Holly walked the dog." This sentence puts focus on the person engaging in the action (Holly) rather than the objected acted upon (the dog).

Eliminate nominalization. Nominalization is unnecessarily using the noun form of a word when the verb form would make the sentence more concise. People often accidentally nominalize a sentence in a first draft.

• To catch unneeded nominalization, look for the word "of" and examine each time you use it in a paper. "Of" is often used in nominalization. For example, "Luke offered an explanation of why Rosemary was late for class."
• As you can see in the above sentence, instead of using the verb "explain" the noun "explanation" is used. The sentence would be quicker and easier to read if it were rewritten as "Luke explained why Rosemary was late for class."

Limit use of the word "there." "There" is an expletive that usually does nothing to clarify the meaning of a sentence. In general, you should remove unnecessary uses of the word "there" while proofreading.

• Sentences that begin with "there," "there is," and "there are" would generally read better with these portions removed. For example, "There are many people who believe free speech should be limited in certain ways." Removing the "there" makes the sentence read more smoothly. "Many people believe free speech should be limited in some way."