How to politely tell my friend to shut up

Been through this, and it's worse early in the morning. Either learn to tune her out and let her ramble on about whatever, or, initiate the conversation yourself and take some talk time away from her. She may get the message that she's blabbing on too much.

Years ago, my job had an intern (in truth..a favor the director did for a board member) from the local college, which was 2 miles from my apartment and on my way to work. She didn't have a car, so, I was asked to drive her. I should have jabbed steak knives into my ears from day one. That girl yapped and blabbed from the time she opened the passenger door of my car, all the way down either the side road or highway, if I needed gas or wanted a coffee, and into the office. I learned to tune her out, and, on the way home, start up myself so she'd shut up five minutes.

Can't tell you the relief I felt when her internship was over. My coworkers knew what I was going through, too.

Punch her

How about, “Shut up, you’re showing your ignorance!”

Talk to someone else during this time. That way when she arrives, you're already in a different conversation. If she then butts in and takes over that conversation she is being really rude, and you then don't need to feel bad/rude about avoiding her.

Just say “Sarah, I’m sorry you’re having problems with your family and friends but I have my own set of issues and am in no place to fix your’s, I’m not saying it to be mean. I just need my mornings to gather my thoughts sometimes.”

She’ll take the hint.

No easy answer.
Some folks love the sound of their own voice.
They'll do a 2 hour monologue and then say 'it was nice talking with you."
As if it had been a conversation.
Try to get a word in, they talk right over you.
1 You can be polite and listen to hours of crap.
2 you can be considered rude and:
A tell her the truth.
B get up and move, sit elsewhere.
C sit there but obviously ignore her,
Walkman volume up.
Anyone have a better idea?

The polite way is to say "PLEASE shut the fuck up!".

I had a friend keep on talking during a lecture I was really interested in at a congress over the weekend and I just shushed her several times until she stopped (although I did it humorously and laughed with her). It was a different kind of talking but still annoying.

Since you won't tell her maybe you should consider not being so close anymore and start by not arriving so early and if you do try talking to other people or saying you have to figure something out and that you need to concentrate on it - like studying something for class or texting someone about something urgent and important. Ah, idk... lol

git up & walk away while shes talkin

Ask her why she always interrupts you, and why can't she let you finish whatever you are saying. Honestly, she sounds a lot like my sister. I don't really hate my sister, but sometimes she makes me feel like I do, because she's so full of herself. It's shit like this that makes me feel like I'd rather not pursue friendship with other people in general. The really shitty thing is that if I look back I can see that I probably used to be the same way too.

Anyway, enough about me, and my bullshit. I think you should ask her why she always interrupts you. That's just my opinion of course. Maybe just tell her you gotta go when she interrupts you too many times in a row? Is she kind of a drama queen?