20 Common Errors in Student Writing

BHSU Writing Center

September 14, 2006


Identifying the 20 Most Common Errors in Student Writing


In their 1988 study, Robert Connor and Andrea Lunsford tallied the most common grammatical errors in 3,000 college essays from across the country.[1][1] The following is the list, by no means comprehensive, that they developed. Frequency of error may shift across time and geographic lines, but this list provides a general starting place for helping us identify where students need to improve their grammar, usage, and punctuation.


  1. No comma after introductory element.
  2. Vague pronoun reference
  3. No comma in a compound sentence
  4. Wrong word
  5. No comma in a non-restrictive element
  6. Wrong/missing inflected endings
  7. Wrong or missing preposition
  8. Comma splice
  9. Possessive apostrophe error
  10. Tense shift
  11. Unnecessary shift in person
  12. Sentence fragment
  13. Wrong tense of verb form
  14. Subject-verb agreement
  15. Lack of comma in a series
  16. Pronoun agreement error
  17. Unnecessary comma with a restrictive element
  18. Run-on or fused sentence
  19. Dangling or misplaced modifier
  20. Its/it’s error