End Punctuation 101

Let's take a look at how to deal with your sentence endings. The three basic choices in end punctuation are the following:

period	question mark	exclamation point
.	?	!

Most of the time, a period will get the job done, but if you're asking a question or being emphatic about something, you'll probably need one of the other two. Read on for details.

Use periods to

• mark the end of a declarative (statement) or imperative (command) sentence
  • Amal prefers ice-skating to inline skating.
• end a sentence expressing a polite request or indirect question
  • Would you please have the plans sent over by the end of the day.
• replace parentheses used with numerals or letters in vertical lists
  1. Education
  2. Experience
     1. Employment
     2. Volunteer
  3. References
• punctuate most abbreviations of single words (etc., Mr.) and abbreviations made up of lower-case initials (p.m., e.g.)
  • We will take up nos. 12-22 next.

  Note: If an abbreviation that ends in a period is the last word in a sentence, no additional period is required.

Do NOT use periods to

• separate letters in most acronyms (radar), initialisms (ISBN), abbreviated compass directions (SW), symbols for units of measurement (mm) or chemicals (KCl), or mathematical abbreviations (tan)

  WRONG: The preferred short form for Government of Canada is G.C.

  REVISED: The preferred short form for Government of Canada is GC.

Use question marks to

• mark the end of an interrogative (question) sentence
  • Do you have the recipe for the coffee cake Ira brought?
• express uncertainty (enclosed in parentheses)
  • Written in 1589 (?), Christopher Marlowe's Doctor Faustus was first published in 1604.

Use exclamation points to

• mark the end of an exclamatory (emphatic) sentence
  • Elke is winning!
• punctuate interjections and exclamations that are not complete sentences
  • Hear, hear!
• express the writer's incredulity (enclosed in parentheses)
  • Imelda Marcos brought the Miss Universe Pageant to the Philippines in 1974—an honour (!) previously reserved for wealthier nations.

  Note: Exclamation points lose their impact with overuse. Whenever possible, allow your words to create the emphasis, rather than relying on punctuation to get the point across.

For more information on end punctuation, see sections 7.03 to 7.12 of The Canadian Style.