When I tell someone my preferred pronouns are they/them/their, I never know what to expect.
Sometimes people just say, "Ok." Other times, they'll ask a whole bunch of questions I don't really feel like answering.
For example, "how can one person be a 'they'?" Answer: it's really simple.
In English, we already use singular they all the time. Suppose you found 50 bucks on the ground, you might say, "Oh, someone dropped their money here."
That's singular they. It dates back to at least the 16th Century and most major dictionaries from Oxford to Webster's consider it to be grammatically correct.
That should be enough. What bothers me most is when I tell someone several times to use they/them pronouns for me, but they make no effort to do so.
Being ignored like that, hurts. It's OK if you get my pronouns wrong by accident, it takes time to adjust to new ways of speaking and thinking.
Just don't make it my problem when you misgender me.
I hope this clears some things up. And next time you're wondering something about pronouns, I'll try to be patient.
But you could also try, I don't know, Google?