A sentence has a subject and a predicate. Do not link two sentences with a comma or run together two sentences with no punctuation.

  • See Essentials of Writing on “Fragment” (26) and “Run-on” (41).


Use a comma to separate two independent clauses separated by and, but, for, nor, or, so, and yet. Use a comma after an introductory phrase or clause. Use a semicolon between two independent clauses not separated by one of these conjunctions.


A singular subject takes a singular verb; a plural subject takes a plural verb. Use a singular pronoun with a singular antecedent and a plural pronoun with a plural antecedent. Some singular pronouns to remember: anyone, each, either, everyone.

  • See Essentials of Writing (18)

Parallel Construction

Sentence elements connected by idea should be expressed in similar form.

  • See The Elements of Style, Rule 19; Essentials of Writing (30)


Use verb tenses correctly and consistently.

  • See The Elements of Style, Rule 21; Essentials of Writing (49); the Writing Center handout "Tense."


Use the active voice, in which the subject acts, unless you have a good reason to use the passive voice.

  • See The Elements of Style, Rule 14; Essentials of Writing (31); the Writing Center handouts and “Active Voice.

Pronoun Reference

Avoid the vagueness of pronouns, especially at the beginning of sentences and paragraphs. Rather than write “This is” or “It is,” use as subject the noun that is the actual subject of your sentence.

  • See Essentials of Writing (35)

Misplaced and Dangling Modifiers

Misplaced modifiers are words or phrases that, due to incorrect placement, refer to the wrong word in the sentence. Dangling modifiers do not refer to any word in the sentence.

  • See Essentials of Writing (23, 28)


Use citations in the proper form to document your use of other writers' words and ideas. Plagiarism is a violation of the Hamilton College Honor Code.

  • See Essentials of Writing (53-54); the Writing Center handouts “MLA Documentation,” “Footnotes,” and “Using Sources.”

Other Errors

“X” marks the spot for other errors. Ask your professor what's wrong, or do the detective work yourself.

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