The Colon except in conventional uses is practically obsolete.

  1. It is generally put at the end of a sentence introducing a long quotation: "The cheers having subsided, Mr. Bryan spoke as follows:"
  2. It is placed before an explanation or illustration of the subject under consideration: "This is the meaning of the term:"
  3. A direct quotation formally introduced is generally preceded by a colon: "The great orator made this funny remark:"
  4. The colon is often used in the title of books when the secondary or subtitle is in apposition to the leading one and when the conjunction or is omitted: "Acoustics: the Science of Sound."
  5. It is used after the salutation in the beginning of letters: "Sir: My dear Sir: Gentlemen: Dear Mr. Jones:" etc. In this connection a dash very often follows the colon.
  6. It is sometimes used to introduce details of a group of things already referred to in the mass: "The boy's excuses for being late were: firstly, he did not know the time, secondly, he was sent on an errand, thirdly, he tripped on a rock and fell by the wayside."

The Period is the simplest punctuation mark. It is simply used to mark the end of a complete sentence that is neither interrogative nor exclamatory.

  1. After every sentence conveying a complete meaning: "Birds fly." "Plants grow." "Man is mortal."
  2. In abbreviations: after every abbreviated word: Rt. Rev. T. C. Alexander, D.D., L.L.D.
  3. A period is used on the title pages of books after the name of the book, after the author's name, after the publisher's imprint: American Trails. By Theodore Roosevelt. New York. Scribner Company.

The Mark of Interrogation is used to ask or suggest a question.

  1. Every question admitting of an answer, even when it is not expected, should be followed by the mark of interrogation: "Who has not heard of Napoleon?"
  2. When several questions have a common dependence they should be followed by one mark of interrogation at the end of the series: "Where now are the playthings and friends of my boyhood; the laughing boys; the winsome girls; the fond neighbors whom I loved?"
  3. The mark is often used parenthetically to suggest doubt: "In 1893 (?) Gladstone became converted to Home Rule for Ireland."

The Exclamation point should be sparingly used, particularly in prose. Its chief use is to denote emotion of some kind.

  1. It is generally employed with interjections or clauses used as interjections: "Alas! I am forsaken." "What a lovely landscape!"
  2. Expressions of strong emotion call for the exclamation: "Charge, Chester, charge! On, Stanley, on!"
  3. When the emotion is very strong double exclamation points may be used: "Assist him!! I would rather assist Satan!!"

The Dash is generally confined to cases where there is a sudden break from the general run of the passage. Of all the punctuation marks it is the most misused.

  1. It is employed to denote sudden change in the construction or sentiment: "The Heroes of the Civil War,—how we cherish them." "He was a fine fellow—in his own opinion."
  2. When a word or expression is repeated for oratorical effect, a dash is used to introduce the repetition: "Shakespeare was the greatest of all poets—Shakespeare, the intellectual ocean whose waves washed the continents of all thought."
  3. The Dash is used to indicate a conclusion without expressing it: "He is an excellent man but—"
  4. It is used to indicate what is not expected or what is not the natural outcome of what has gone before: "He delved deep into the bowels of the earth and found instead of the hidden treasure—a button."
  5. It is used to denote the omission of letters or figures: "J—n J—s for John Jones; 1908-9 for 1908 and 1909; Matthew VII:5-8 for Matthew VII:5, 6, 7, and 8.
  6. When an ellipsis of the words, namely, that is, to wit, etc., takes place, the dash is used to supply them: "He excelled in three branches—arithmetic, algebra, and geometry."
  7. A dash is used to denote the omission of part of a word when it is undesirable to write the full word: He is somewhat of a r——l (rascal). This is especially the case in profane words.
  8. Between a citation and the authority for it there is generally a dash: "All the world's a stage."—Shakespeare.
  9. When questions and answers are put in the same paragraph they should be separated by dashes: "Are you a good boy? Yes, Sir.—Do you love study? I do."