human
I'm a little confused about how to properly use apostrophes in my writing. Can you give me some tips?
assistant
1.  Use an apostrophe to indicate the omission of letters or sounds from a word.
2.  Apostrophes are also used to form contractions, such as don't for do not and it's for it is.
3.  When using an apostrophe to form a plural noun, make sure to include the s at the end, like cats' tails.