On iPhone can you still look at someone's history once they clear it?

I was just wondering ^^^

Nope. Unless you connect the phone to a computer and you seriously know what you're doing. When something is deleted only the record of it being there's erased but the physical bytes are still on the hard drive so if you were clever enough you would be able to get it before the files were overwritten but for a simple user it's not possible. Sorry.