I'm trying to wrap my head around whether any of the following are correct (apart from #3):
1) One of the tools I use is magnets.
2) One of the tools I use are magnets.
3) One of the tools I use is the magnet.
For #1, I'm not sure if it's correct or not. The assumption I'm making here is that "magnets" could be a collective, but I could be wrong.
For #2, since "one" is the subject, I'm fairly certain it's wrong.
For #3, I'm sure it's correct, but it doesn't have the same effect of plurality that I want to convey.
Any ideas or advice? Would greatly appreciate it.