Are any apostrophes needed in the following sentence? If so where?: Their houses doors all had to be the same color.
Yes, in the word 'house' --> Their house's
I don't know how to explain it but, I think the time when you use that (') is when your referring to a possession.
are you going to John's birthday
that's John's stuff
Also, you could use this website: grammarly.com
I'ts free. It helps correct any grammar mistakes US or UK style.