[Yonathan G]

I just got fortress and said "call dad". Cortana then asked what my dad nickname was. When I said it, Cortana misunderstood and thought that I said my friends name, who is in my contacts. Now, whenever I say "call dad," Cortana asked "which dad?" The other contact is my friend, and I'm pretty sure he isn't my dad.

[MDK22]

Go to Cortana, hit the hamburger menu (upper right) & edit it in INNER CIRCLE.
You should have both contacts listed with 'dad' underneath

[humanhowever]

I just got fortress and said "call dad". Cortana then asked what my dad nickname was. When I said it, Cortana misunderstood and thought that I said my friends name, who is in my contacts. Now, whenever I say "call dad," Cortana asked "which dad?" The other contact is my friend, and I'm pretty sure he isn't my dad.

LOL. That just made me laugh. But the person above is right. :)

[Hypnopottamus]

Best way to do this is actually in the person's contact card. Go to the People Hub, find the contact, hit the edit button. Edit the contact using your MS account (Hotmail, outlook, live). From there, in the "Name" field, you'll see a "+" . Hit that, and scroll all the way to the bottom. You should see an option that says "add Cortana nicknames."