Google Now is great, but it's not perfect. Sometimes it doesn't hear you quite right. If that happens though, you don't have to repeat the whole command; just tell Google the word it got wrong with "No, I said..."
As 9to5Google explains, maybe you asked for "nearby bars" but Google inexplicably gave you results for nearby cars. If you just say "OK Google: No, I said bars" Google Now will correct itself and then search for what you meant in the first place, presumably because it can figure out which word is most likely to be wrong.
It'd be better if "No, I said" was a voice search trigger word so that you didn't have to say "OK Google" again like a chump, but it's still a convenient little trick that makes asking your phone (or watch) questions feel a little less robotic and a little more personable. You'll be having real conversations with your own personal HAL in no time. [9to5Mac]