20 Most Common Grammatical Errors in Student Writing

A working list of the most common errors can be helpful in writing, editing or teaching, even though the list will change constantly. Newsroom 101 provides practice on the items in this list, along with other types of errors, in addition to covering issues specific to journalism and AP style.

Each error is followed by an example illustrating it.

  • No comma after introductory element
    • Because it was raining we did not play softball.
  • Vague pronoun reference
    • Today he forgot his book. Yesterday he forgot about the quiz. It’s too bad he did that.
  • No comma in compound sentence
    • We were here yesterday and we worked six hours.
  • Wrong word
    • Sixty seniors matriculated from college last summer.
  • No comma in restrictive element
    • One of my students George left this book for you.
  • Wrong or missing inflected endings
    • Who do you mean?
  • Wrong or missing preposition
    • When did you graduate college?
  • Comma splice
    • We had a good time, we played softball.
  • Apostrophe error
    • That is the Jone’s house. We visited two house’s.
  • Tense shift
    • “Says” and “said” used interchangeably in an article.
  • Shift in person; sexist pronouns
    • It is important for one to bring his book to class.
  • Sentence fragment
    • Not alone in thinking this is wrong.
  • Wrong tense or verb form
    • He had drunken the whole gallon of juice.
  • Subject-verb agreement
    • He is one of those athletes who practices twenty hours a day.
  • Comma in a series
    • hook, line, and sinker (specific to AP style)
  • Pronoun agreement error
    • Each student should bring their book to the exam.
  • Unnecessary comma with restrictive element
    • This is the house, that Jack built.
  • Run-on or fused sentence
    • We had a test I did well on it grammar is my forte.
  • Dangling or misplaced modifier
    • Not knowing grammar, the test was hard.
  • Its/it’s error
    • The dog is chasing it’s tail.

Suggestions:

  • Find your own examples for each error. Have students find examples.
  • When you discuss an error, ask students to find out if it appears in this list. (This activity will familiarize them with the list.)
  • Identify common errors that do not appear in this list.
    • Due to texting, for example, today’s students may not properly capitalize words, and they sometimes use abbreviations without realizing it.
    • Since the research was conducted to derive this list, you more often see the objective case used as the subject of a sentence — e.g., “Me and him agree that case matters.”
    • Journalists may inadvertently use the odd, compressed language of headlines in the body of a story without realizing it.

Expanded by Gerald Grow from R. J. Connors and A. Lunsford, “Frequency of Formal Errors in Current College Writing, or Ma and Pa Kettle Do Research,” in The St. Martin’s guide to Teaching and Writing, ed. R. J. Conners and C. Glenn (New York: St. Martin’s Press, 1992), 390-406.