I don't realy know 和 I really don't know 有何区别

i really don't know sorry,I really don't know---------- I really don't know where to I don‘t know I don't know I don't know. I DON'T REALLY KNOW 还是 I really don't know I really don"t know.I don"t really know.哪句话对?THANKS 貌似歌词中有：i really don‘t know what to do i really don’t know to i cann't answer,because i really don't know. i cann\'t answer,because i really don\'t know. I don't know anything 和 I don't know nothing的区别