Sword - heard someone pronounce it with the "w", kind of like "toward". The w is silent, pronunced like "board".
Prerogative - the first "r" is silent. Often misspelled.
I pronounce "sword" with the W. I'm not sure why, I just always have. I know it's not supposed to be pronounced like that, it's just so drilled into me by now that it's hard for me to change my ways, hehe.
However, I must respectfully disagree about the pronunciation of the word "prerogative." I actually had to look it up because I thought, "Maybe I've been saying that one wrong the whole time, too." LOL.
(Quoted from Google)