Can I use my Iphone as a phone again?

Ok long story short,
I was living in another country and I asked a friend of mine if he could unlock my old Iphone so I could use it in the country that I was living in. Well the guy wasn't able to unlock the Iphone and some stuff happened so it could only be used as a touch Ipod.
Well I'm going to be moving back to the states will I be able to use my Iphone when I get back to the States if I put in my US sim card or is my Iphone not able to be used as a phone anymore?

Probably not, assuming your phone has a bad esm now

In which network you are using currently? Note: If you want to use your iPhone from one country to another, you need to unlock it officially. Once, your iPhone gets unlocked by a proper service, you can able to use it with any other GSM networks in different countries. To unlock your iPhone, contact your current service provider or get Remote unlocking method from any of the online vendors like http://www.theunlockspot.com/apple-iphone/rs16wp9/ to unlock your iPhone. After unlocking your iPhone, you can easily use any GSM states sim with it.