My mom is always in a negative mood. She starts talking about negative stuff, which makes my dad angry and yell at her. She doesn't shut up, so the result is a lot of loud fighting and arguing. I want both of them to resolve this, but they won't unless either my mom stops saying negative things or my dad accepts them. Frankly, I just want them to shut up so I can do my work

How old are you?

How long have they been fighting?

Have you sat down and told them that it hurts your feelings that they fight and yell?

I hate to say this, but being a child of divorce it sounds like it could head that way.
There's lots of steps they could take to prevent this (counselling, date nights, etc) but if it's at the end of the rope, it's out of your hands.
It's obvious you really want to help them, so maybe put some energy into things to bring them together and take away some stress.Maybe have separate talks with both of them, about a nice memory you have of them being happy together, or cook a dinner for them.
All you should hope for is that they both end up happy, because they're your parents... Unfortunately, even if they're not together anymore.

My mum and dad used to fight all the time. My dad would start on my mum and she yell back. I used tobe able to drown it out or put music on up loud. Then as I got older I couldn't just ignore it anymore. I used to get between then and scream stop. My mum would stop straight away . My dad would stop after I told him to shut up. This went on for a few years until I told my mum either he goes or I do. Naturally mum chose me.

Don't let it get that far. Say something now. Tell them how you feel tell them how it effects you.

There is one things parents should never do and that fight in front of their kids.

Unfortunately you are a witness to that just because two people are married doesn't make everything is going to be played out as in a fairy tale. A lot of Mom and Dad's argue and yes it can get ugly to have to witness. When we are so stuck in the moment of trying to prove we are right to the other person, we forget sometimes forget we are hurting those we love. Please try to sit down with your parents when they aren't upset and calmly explain how their fighting is upsetting you. This would also be perfect time to maybe suggest counceling for the family, let them know that you would even be willing to go with them if that would help the situation. If you have siblings let them be included. Good luck

At this point the best thing you can do is wait for a time when they are not arguing or fighting, and say 'mom dad, I have something to tell you' and just lay it out. 'i feel ____ when you guys ____' get all of your feelings out.

Its possible that them seeing how it is affecting YOU, may be the slap in the face they need to seek counseling.

Good luck hon. If all else fails, speak to a grandparent, aunt, uncle, or teacher.