ANSWERS TO APOSTROPHES EXERCISE

1. The researchers’ discoveries have allowed for new advances in AIDS research.  

(correct)

2. It is becoming possible to mix various animals' genes.  

Animal's has to be changed to animals' because the word "various" signals you that the word is plural. 

3. Will a lower fat diet affect people's overall health?  

The apostrophe needs to be moved before the "s" in this example because "people" is already a plural word.

 4. A ten minute’s delay between classes allows you to get from one class to another.  

(correct)

 5. I plan to improve last semester's GPA by at least a letter grade!  

The apostrophe needs to be moved before the "s" in this example because you are referring to only one semester.

 6. The children’s room was filled with toys.  

(correct)

 7. Peter didn't want to live in the men’s dorms for more than one year.

You need an apostrophe before the "t" in didn't since this is a contraction for "did not." 

8. Everyone’s essays were due on Friday.  

(correct)

 9. My sister's boyfriend is housesitting at somebody’s mansion during September.  

You need an apostrophe before the "s" in sister's because the sentence is referring to only one sister; the apostrophe with "somebody's" is okay.

10. My parent’s farm is located in Breeze.  

(corrrect)

11. This year's distinguished speaker series is excellent.  

You need an apostrophe before the "s" in "year's" since you are referring to a single year. 

12. It's going to be hard to work more than 20 hours this semester given the amount of homework I have.

You need an apostrophe with "It's" since this is a contraction for "it is."