Use apostrophes in two in two main instances:
- to show possession
- in contractions
Singular words, whether or not they end in s, are made possessive by adding an apostrophe + s. For plural words that end in s, indicate possession simply by adding the apostrophe at the end without an additional s. However, for a plural that does not end in an s (e.g., bacteria), add an apostrophe + s. For example:
- a student’s paper
- one hour’s passing
- Illinois’s law
- interviewees’ answers (more than one interviewee; if it were just one, you would write interviewee’s answers)
- her professors’ office (an office shared by two or more professors; if it were just one professor you would write her professor’s office)
A contraction is a shortened phrase. He will becomes he’ll, are not becomes aren’t, would have becomes would’ve, and it is becomes it’s. In all of these cases, the apostrophe stands in for the missing letters.
Other Apostrophe Uses and Misuses
Apostrophes may also be used to clarify words such as “mind your p’s and q’s.” However, only use apostrophes to clarify information when it would be confusing not to use it (ps and qs is confusing without the apostrophe). For example, you write “1920s America” or “CDs are now almost obsolete technology” without the apostrophe.
One common misuse of apostrophes is in names, incorrectly substituting an apostrophe for a plural. You may see a sign in front of a house that says The Jones’. If the Jones family meant to indicate that many of them lived there, which is usually the case, then the names should be pluralized: The Joneses. The apostrophe shows possession, and would need to be clarified by adding the possession intended, e.g., The Jones’ house.
Finally, note that you do not need an apostrophe with a pronoun that shows possession (e.g., theirs, yours, ours, his, hers).
View the following video on apostrophes.
Read the following passage. Identify any errors with apostrophes. Type the corrected words in the text frame below:
Thanks to NASAs’ team of sniffers, led by George Aldrich, astronauts can breathe a little bit easier. Aldrich is the “chief sniffer” at the White Sands Test Facility in New Mexico. His’s job is to smell items before they can be flown in the space shuttle.
Aldrich explained that smells change in space and that once astronauts are up there, their stuck with whatever smells are onboard with them. In space, astronauts aren’t able to open the window for extra ventilation. He also said that its important not to introduce substances that will change the delicate balance of the climate of the International Space Station and the space shuttle.
Use double quotation marks in three instances:
- writing a direct quotation from another source
- calling attention to a word, or using a common word in a special way (use in special cases only; do not overuse)
- identifying a chapter or a smaller piece of a text (a title of the whole text usually is put into italics)
- He said “I’ll never forget you.” It was the best moment of my life.
- Yogi Berra famously said, “A nickel ain’t worth a dime anymore.”
- I can never say “Worcestershire” correctly.
- The article, “Seven Ways to Prepare Stew,” is an interesting addition to September’s Cooking Common magazine.
Use single quotation marks in one instance:
- for a quote within a quote
- Stephen asked, “Do you know which Shakespeare play contains ‘the quality of mercy’ speech?”
Commas and periods always go inside the end quotation marks.
- Correct: The people of the pine barrens are often called “pineys.”
- Incorrect: The people of the pine barrens are often called “pineys”.
- Correct: “Because I like baseball so much,” Harry said, “my family tends to give me trips to different ballparks for my birthday.”
- Incorrect: “Because I like baseball so much”, Harry said, “my family tends to give me trips to different ballparks for my birthday.”
Semi-colons, colons, and dashes always go outside of the quotation marks, unless these punctuation marks are actually part of the original quotation.
- Correct: This measurement is commonly known as “dip angle”; dip angle is the angle formed between a normal plane and a vertical.
- Incorrect: This measurement is commonly known as “dip angle;” dip angle is the angle formed between a normal plane and a vertical.
Question marks and exclamation points can go either inside or outside of the end quotation marks, depending on whether the punctuation mark itself is part of the quotation. If it is, then the question mark or exclamation point stays inside the end quotation mark. If it is not, then the question mark or exclamation point goes outside the end quotation mark.
- When she was asked the question “Are rainbows possible in winter?” she answered by examining whether raindrops freeze at temperatures below 0 °C. (Quoted material retains its own punctuation.)
- Did he really say “Dogs are the devil’s henchmen”? (The quote is a statement, but the full sentence is a question.)
- I’m amazed that Carlos said “cats are preferable to dogs”! (This sentence is correct, because the initial phrase indicates that the sentence writer is the one amazed; Carlos’ quotation is a statement and not exclamation. If the exclamation point were inside of the end quotation mark, it would make Carlos’ statement an exclamation, which is not what the initial phrase indicates.)
The following video reviews quotation mark usage.
Has the following passage been punctuated correctly? Type any corrections in the text frame below:
Gabrielly and Marcelo both knew a lot of “fun facts” that they liked to share with each other. Yesterday Gabrielly said to Marcelo, “Did you know that wild turkeys can run up to twenty-five miles per hour?”
“Well, an emu can run twice that speed,” Marcelo responded.
“Did you know that there’s a dinosaur-themed park in Poland called JuraPark Bałtów”? Gabrielly asked.
Marcelo then told her about “Rusik, the first Russian police sniffer cat, who helped search for illegal cargoes of fish and caviar”.