Can I make calls using speakout while in the US? | Technical service details | Consumer forum

I have an old phone that currently has speakout SIM card. I think the phone is 3G. A friend will give me an old iPhone that can do 4G. Can I put the sim card in the iPhone and it will work without me doing anything else?

Also, I read this:

You cannot make calls with your Canadian 7-Eleven Speak Out Wireless phone if you are in the US

It says I can't make calls with the Speak Out Wireless Phone in the US. Is that because the Speakout phones are 3G only? Does it matter if the phone I have can do 4G? Or will speakout still not work in a 4G phone in the US?