Semicolons, Dashes, Parentheses, and Commas

  1. The semicolon has two primary uses. First, it is used to join together two main clauses that could be separated by a period; second, it is used for clarification when there are multiple commas in a series.
    1. A semicolon may join two main clauses, each of which could stand alone.
      • It would be wise to take umbrellas; those clouds coming from the north look ominous.
      • I hope that Jill will be able to play; she is the best forward we have ever had.
    2. A semicolon may also join two main clauses which are joined by conjunctive adverbs, such as therefore, hence, however, nevertheless, accordingly, on the other hand, thus, then.
      • The day was cold and blustery; therefore, we did not go out jogging.
      • Many people like butterscotch on ice cream; however, those with refined tastes prefer chocolate.
    3. In addition, semicolons may replace commas in a series to avoid possible confusion.
      • He has lived in Buffalo, New York; Shreveport, Louisiana; Afton, Wyoming; and Ivins, Utah.
      • We took exams on September 2, 1999; November 15, 1999; and December18, 1999.
  2. The dash is for an abrupt break in thought (the highest degree of interruption). Such a dash points the reader's attention to the material within the dashes or following a single dash.
    • One of them—-let me call him Jim Prude–is an Ivy Leaguer.
    • In some instances–although few will admit it–the police overreact to situations.


      1. The dash can be used to mean "that is to say" before an explanation.
        • Jefferson believed in a decentralized governmental system–the political power was to be in the hands of the people.
        • Our hearts usually go out to those with a terrible affliction–the exception may be the too-common response to those with AIDS.
      2. Use a dash when the word or word group that follows it constitutes a summation, an amplification. or a reversal in tone or idea from that which went before it.
        • English, psychology, history, and philosophy–these were the courses I took last quarter.
        • If he was scolded, he became violent–a reaction all of us resented.
        • Emily Dickinson probably overused the dash–but with a brilliant effect.
      3. Use a dash to introduce an internal list of items.
        • As we drove through Zion National Park, many animals–snakes, squirrels, wild turkeys, and deer–appeared on the side of the road.
  3. Parentheses are used for incidental, explanatory information (the middle degree of interruption).
    • All the students were charged a paper fee (usually 50 cents) during the last two school years.
    • During the post-war years (at least from 1946 to 1952), the law was not challenged.
  4. Commas are used for breaks in the flow of the sentences (lowest degree of interruption). A comma points the reader's attention forward to the material that is yet to come.
    • The professor, the man on your left, is a noted occult authority.
    • Her theory, while I can't be absolutely positive, is not original.