Punctuation is often mis-used, sometimes with amusing results. Check the rules for the use of quotation marks and apostrophes in Chapter 14 of your textbook, and then visit these two sites:
http://www.juvalamu.com/qmarks/ http://www.nuff.ox.ac.uk/Users/Martin/APOST/Apostrop.htm
Write a memo to you instructor explaining some of the examples of mis-use and the reason they are amusing.