On Macbook keyboard, h key is acting like alt

Hello,

Last night, I was typing a Word document when suddenly my "h" key began looking like this when i typed it --> ?
I have no idea how to fix it. I researched it a lot online and found out that the h key is acting like the alt key! If I hold down the h key and press another key, it makes symbols. I didn't do anything abnormal, I was just typing. Please help! I have to write a paper and it is due today!