How to use home internet instead of iPhone 4's free internet on it?

I can't use my new iPhone 4's free Wi-Fi, so I'm trying to use the house's. The thing is, I'm scared I might use the phone's Wi-Fi accidentally, and I'm trying to make sure I don't. I switched the Wi-Fi network to my house's internet.

I can't tell the difference between the phone's free Wi-Fi or the house's. So I'm just wondering, if I leave the house and use a game app that uses the internet, but I have Wi-Fi off, will the phone's Wi-Fi be used? Or will the game just not work since I have Wi-Fi off?

XD you have no idea wtf tecknology is do you! If you have a phone service that gives you unlimited internet then you use it all the time! If you want faster inter net or whatever then you must have Wi-Fi on your house! Then just go to settings and turn Wi-Fi on! It. Will have 3 triangle lines on the top left side telling u your on Wi-Fi if it doesn't have it your using phone internet