Are the following sentences natural to a native ear?
1. If anybody opposes Friday night, please let me know.
2. Just by show of hands, how many people are interested in a karaoke event?
3. We got be cognizant of the fact that we have done a mistake, but we should also not keep rooting about it forever.
Sorry to bother.....Just by a show of hands, how many people are interested in a karaoke event? OK
I think it sounds better : Just by a show of hands, how many people are interested in the karaoke event.
There is not necessarily a karaoke event yet, so "the" won't work unless it's already been discussed. If the speaker is raising the idea for the first time, then "a" is needed.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.