Instructions: Insert apostrophes where needed. Not every sentence needs an apostrophe.
Remember that apostrophes signify “of” ideas (Mary’s car = car of Mary).

1. She always holds her childrens birthday parties at a skating rink.
2. Parents never forget the thrill of watching a babys first step.
3. I’ve known the Thompsons since 1984.
4. I stayed at the Smiths party until three in the morning.
5. Two days work was lost when the computer system went down.
6. The puppies yelping keeps me from studying.
7. Last months bills were sent out yesterday.
8. This buildings exits are clearly marked.
9. Both patients X-rays were taken this morning.
10. On Tuesdays, the technology staff meets from one to three.

Click here for the answers.