Can you put a normal contract sim card into an iphone 4?

Hi can anybody help as i'm new to iphones and currently have a basic phone i'm looking to buy an iphone 4 from ebay, will my contract sim card fit into an iphone 4 if not what do I do and where do I get one from ect?

Before put your contract Sim, Make sure your new iPhone 4 is unlocked and accept your current sim size. If it's locked by particular network provider means, You will need to unlock iPhone. For iPhone unlocking you can approach your service provider or else try to buy an unlocking service from any one of the online unlocking service provider like http://www.wickedunlock.com/apple-iphone-4/rs5wp9/ I hope it will be very useful to you.

The iPhone 4 uses microSIMs as opposed to what I assume is a miniSIM. You'd have to either cut it down to size or get a microSIM with your number on it. Of course your carrier would be the place to do that.

Also, and more importantly, the iPhone would either have to be locked to the carrier you are on now or unlocked for any of this to matter.