Which sentence uses a contraction or possessive form incorrectly?
a. i can't believe your going to be in high school next year.
b. my sisters want to paint their bedroom pink.
c. there's only one post office in the small town.
d. we're going to leave around noon.

The sentence that uses a contraction or possessive form incorrectly is A. I can't believe your going to be in high school next year. The mistake here is the word your - it should be you're, because that is short for you are, and your is a pronoun denoting possession: your cat, your dog, but You're wrong, meaning You are wrong.The remaining sentences have no mistakes in them.

d.

Ottawa is the capital of Canada, but Toronto is the capital of Ontario.

Explanation: