Would you tell a coworker , whom you MUST sit by for 8 hours that they are condescending sometimes?

I think honestly people like that need that in your face talk. I don’t mean being nasty but “listen, stop rephrasing everything I say and butting into every conversation I have. We don’t need an echo to what I am saying. You need to be respectful of my time here also. 8 hours is a long time for me to bite my tongue. I’m hoping things change and my work environment improves. I need to make a living also”. Or you can just tell her to butt the hell out and myob.

Gross. So sorry.
It sometimes works to deflect this stuff back to the person but since you have to work together please be as respectful and genuine as you can be.

The next time you feel she has gone off the snarky cliff, stop what you're doing and tell her sincerely, "I am so sorry you're having a bad day." Or " dealing with * fillintheblank*." If she's likely to snap back, "No I'm not!" Use the second option. She cant deny what she is clearly complaining your ear off about. Tell her it's unfortunate the topic is taking up her time, energy etc.
Be genuine about this, because you ARE sorry she feels compelled to act this way.
A rational person should get the message they are being perciev3d as negative (well they ARE) and refocus.Good luck🌺

Those are the worst. 😖

I'm not sure she would take it well or do anything to improve. Does she do this with everyone or just you?

The first requirement of good manners is that you put up with people who don't have good manners. After all, your upbringing was a gift to you: you didn't learn good manners by your own efforts. You should not assume bad things about somebody just because they were not given that gift.

I would. I have a habit of shutting people down like that when they annoy me to that level regardless of the consequences. I would not and don’t have to work like that.

She sounds like the worst thing about a bad job.

Yes I would.

Headphones

Just do your own thing and limit your conversations with her.