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Sentence-Level Mechanics

What is a comma splice?

A comma splice is a common sentence problem that occurs when two complete sentences (independent clauses) are incorrectly joined by a comma. This incorrect union of clauses creates a run-on sentence. The problem can be repaired when a different form of punctuation replaces the comma, a coordinating conjunction is inserted, or when the sentence is rewritten.

To avoid confusion, use a comma after an introductory subordinate clause or phrase:

  • Because the costs of conducting research continue to increase, we need to raise our rates.
  • As the shrimp boats trawl, sea grass can collect on the trap door, allowing shrimp to escape.
  • According to the professor, rich women are more likely to have Cesarean sections than poor women.

In keeping with the modern trend toward using as little punctuation as possible, some stylists believe that it is not necessary to place a comma after short introductory words (now, thus, hence) and phrases (In 1982 he committed the same crime).

Create emphasis and define terms by interrupting the flow of a sentence by using a dash; know when the dash must be used as opposed to the comma.

Some stylists view the dash with great suspicion--the sort of suspicion that a man in the 1990s who wears a plaid leisure suit to work would arouse. Some people erroneously believe that the dash is acceptable only in informal discourse.

However, the dash can provide you with subtle ways to repeat modifiers and dramatic ways to emphasize your point.