1. A sentence fragment results when a phrase or a dependent clause is treated as if it were a complete sentence. Correct a fragment either by attaching it to the previous sentence or by adding the right words to the fragment to make it a complete sentence.
2. A comma splice occurs when a comma instead of a period or a semicolon separates two independent clauses. There are four ways of correcting a comma splice:
   1. Separate the independent clauses with a period.
   2. Separate the independent clauses with a semicolon.
   3. Join the independent clauses by a comma and a coordinating conjunction.
   4. Subordinate one independent clause to the other.
3. A run-together sentence occurs when one sentence is piled on another without any kind of punctuation, often resulting in an incoherent passage. Correct a run-together sentence by placing a period or a conjunction between the two sentences.
4. An error in agreement occurs when the subject does not agree with the verb or when a pronoun does not agree with its antecedent. Avoid errors in subject-verb agreement by learning to recognize the subject of a sentence. To avoid errors in pronoun agreement, learn which pronouns are plural and which are singular.
5. Case errors most commonly occur when a student fails to distinguish between the subject and objective cases. The subject is always a noun or pronoun that the predicate says something about. The subject answers “who?” or “what?” about the predicate. The object, on the other hand, receives the action of the verb and is not the same as the subject.
6. Errors in point of view occur when the writer needlessly shifts person, tense, mood voice, or key words.
7. Reference errors occur with the use of pronouns that do not stand for anything specific. Every pronoun must have an unmistakable antecedent.
8. Dangling modifiers occur when words or phrases are used that have no logical relationship to any other element in the sentence. These words simply "dangle" in front of the reader, causing mystification and mirth. The most frequent dangling errors are caused by (1) misused verbal phrases and (2) misused subordinate clauses. To correct dangling elements, assign the logical subject to all verbal phrases or subordinate clauses.
9. Misplaced modifiers occur when modifying words, phrases, or clauses are not placed as close as possible to the words they modify. Confusing, illogical, or awkward sentences are caused by misplaced modifiers.
10. Lack of parallelism occurs when similar grammatical constructions are not used to express parallel ideas. The result is a disruptive break in the rhythm of writing.
11. Poor diction (also called poor word usage) refers to the use of a word to mean something other than its dictionary definition or the use of a word in a way unacceptable to standards of users of ideal English. Ideal English can be defined as language spoken or written according to standards of educated people. It is the language of good books, magazines, and newspapers. People who follow precise standard usage rules are using ideal English, although they probably express themselves less formally in day-to-day communication--on the bus, in the Laundromat, or in the supermarket.

Ideal English is the language of concentrated formality. Dun J. Li, introducing a textbook on Chinese civilization, uses ideal English when he states: “Of all ideologies that influenced the thinking and life of traditional China none was more important than Confucianism.” On the other hand, the irate factory worker complaining about his wages uses colloquial English when he writes, "If you wasn’t so darn pigheaded, you’d raise our pay." Both messages are clear, but the difference is in their levels of formality.

Because it is highly precise, ideal English is generally required in student writing. Colloquial, substandard, or slang words are unacceptable in ideal English. If you are unsure about a word’s meaning, we suggest that you look it up.