1 Missing comma after an introductory element

2 Vague pronoun reference

3 Missing comma in a compound sentence

4 Wrong word

5 Missing comma(s) with a nonrestrictive element

6 Wrong or missing verb ending

7 Wrong or missing preposition

8 Comma splice

9 Missing or misplaced possessive apostrophe

10 Unnecessary shift in tense

11 Unnecessary shift in pronoun

12 Sentence fragment

13 Wrong tense or verb form

14 Lack of subject-verb agreement

15 Missing comma in a series

16 Lack of agreement between pronoun and antecedent

17 Unnecessary comma(s) with a restrictive element

18 Fused sentence

19 Misplaced or dangling modifier

20 Its/It's confusion

Learning from the Twenty Most Common Errors

Grammar, punctuation, and other sentence-level matters will seldom draw much attention unless they interfere with the meaning you're trying to get across. Because they do get in the way, however, they are important to your success as a writer.

What kinds of surface errors are you likely to find in your writing, and how will readers respond to them? Our study of college writing patterns revealed that spelling errors are by far the most common type of error, even with spell checkers, by a factor of more than three to one. Our study also showed that not all surface errors disturb readers, nor do instructors always mark all of them. Finally, not all surface errors are consistently viewed as errors. In fact, some of the patterns identified in our research are considered errors by some readers but stylistic options by others.

While many people think of correctness as absolute, based on hard and fast unchanging "rules," instructors and students know better. We know that there are rules, but that the rules change all the time. "Is it okay to use I in essays for this class?" asks one student. "My high school teacher wouldn't let us." "Will more than one comma error lower my grade?" asks another. Such questions show that rules clearly exist but that they are always shifting and thus need our ongoing attention.

Our research shows some of the shifts that have occurred in the last century alone. Some mechanical and grammatical questions that are of little or no concern today used to be perceived as extremely important. In the late-nineteenth century, for instance, instructors at Harvard said that their students' most serious writing problem was the inability to distinguish between the proper uses of shall and will. Similarly, split infinitives represented a serious problem for many instructors of the 1950s. Nowadays, at least since the starship Enterprise set out "to boldly go" where no one has gone before, split infinitives seem to wrinkle fewer brows.

These examples of shifting standards do not mean that there is no such thing as "correctness" in writing-only that correctness always depends on some context. Correctness is not so much a question of absolute right or wrong as it is a question of the way the choices a writer makes are perceived by readers. As writers, we are all judged by the words we put on the page. We all want to be considered competent and careful, and writing errors work against that impression. The world judges us by our control of the conventions we have agreed to use, and we all know it. As Robert Frost once said of poetry, trying to write without honoring the conventions and agreed-upon rules is like playing tennis without a net.

Since you already know most of these rules, the most efficient way to proceed is to focus on those that are still unfamiliar or puzzling. To aid you in this process, we have identified the twenty error patterns (other than misspelling) that were most common among U.S. college students in the late 1980s and list them here in order of frequency. These twenty errors are likely to cause you the most trouble, so it is well worth your effort to check for them in your writing. This area of the Web site for The New St. Martin's Handbook includes brief examples and explanations of each error pattern; for more detail and additional examples, should consult The New St. Martin's Handbook itself.