Originally Posted by VendingMachine
No, you can only have one native language. Whoever says they have more than one are deluding themselves. Yes, it is possible to speak other languages with near-native fluency but you can only have one mother tongue.
Question is, how do we find out what a person's native language is if he/she is claiming to have two or more native languages? Well, we used to have a very simple way of finding out (somewhat cruel though, but very effective) - you just beat that person real bad and I mean real bad, like with clubs, etc., the important thing is you knock'em sensless. When they come to, the first phrase will always be in their one and only mother tongue. Simple as that. Hundreds of thousands of moles have been uncovered using this simple method.