How to Use Periods
A period is used to indicate that a sentence is a statement or a command.
- Statement: I completed my homework on time.
- Command: You need to finish your homework before it’s due.
Periods with abbreviations
Periods are used in some abbreviations. When an abbreviation with a period is used at the end of a sentence, don’t use an extra period to end the sentence.
- Example: I asked her to come at 10 a.m.
Periods with quotation marks
Periods should be placed inside a quote.
- Correct: Morticia said, “The graveyard is very beautiful.”
- Incorrect: Morticia said, “The graveyard is very beautiful”.
Use a comma instead of a period if the end of a quote is not the end of the sentence.
- Correct: “The graveyard is very beautiful,” Morticia said.
- Incorrect: “The graveyard is very beautiful.” Morticia said.
Periods with parentheses
Sometimes parentheses come at the end of a sentence, such as when citing a source or making a side comment. Punctuation should always come after the end of the parentheses.
- Example: The study measured “cooperative play in baby kittens” (Jones 1).
- Example: The art exhibition was a huge success (thanks largely to Gerard’s help).