If you swear on someones life will they die?

no it is just a myth, highly religious people believe in this but there are no cases (no evidence) that if you swear on someones life they will die

^^ Not necessarily true up-man^^. Not all religions believe this, quite frankly I do not know of any. No, they will definitely not die. Saying, "I swear on my life man!", is just an expression, even if someone seriously means it. No one can die from this, and if they die in the time frame that you said this then it is just coincidence.