Dear Amy: About five months ago my friend "Stacy" fell on some hard times. When her car's transmission went kaput, I offered her rides to her job.

Stacy has been very good with reciprocating favors, contributing gas money, buying us groceries, etc. But reciprocation isn't my issue. It's that my husband and I seem to have become a taxi service for her, including rides to the store and running errands related to her job.

I just learned that Stacy is going on a week's vacation to visit a friend. It occurs to me that if she has saved enough money for a vacation, she could have had a replacement car by now.

I'm all about helping someone for a temporary period of time, but now I feel like my whole life revolves around Stacy's needs. I don't want to lose a friendship, but I want our lives back!

What's the nicest way to end our taxi service?

Amy says: You might start with a question: "How's your search for a new car coming?"

No matter how Stacy responds, you should say: "I'm giving you a heads up, here. We've been happy to help you out, but it's been six months, and our transportation help is going to stop as soon as you're back from vacation."

You should not have to invent an excuse or a reason for this, but it might help you to keep a statement in your pocket: "If you find a car you'd like to look at, we'd be happy to take you to look at it."

Otherwise, there's Uber.

Loves bad news

Dear Amy: I've known "Julia" for more than 20 years. We live hundreds of miles apart but stay in touch.

I try to be a good listener through all of Julia's ups and downs, but she is mostly a negative, bitter person who finds fault with everyone. I rarely hear her say anything good about anyone.

She expects people to cater to her, but doesn't reciprocate. I think friendship is a two-way street.

We all experience good things and bad things, but Julia is not interested in hearing about anything good in my life. But the bad things I tell her about seem to make her happy.

Is this just pure jealousy on her part? Is this even a friend? I'm having my doubts whether Julia is truly a friend, or if I'm just wasting my time. What's your opinion?

Amy says: Julia is demonstrating how schadenfreude fuels her relationships. Schadenfreude is defined as taking pleasure from the misfortunes of others.

You might be wasting your time trying to keep this relationship alive, but before you exit, you might tell her how you feel about her behavior and the impact it has on you. She might not realize the loop she is circling.

The opposite of schadenfreude is "freudenfreude" (yes, it's a thing!), which is taking pleasure from the good things that happen to others. You might ask Julia to share a good thing from her recent life. Respond by expressing your delight. Tell her, "Yes — that felt good!"

Test run

Dear Amy: I'm responding to the letter writer who was looking for advice about whether to adopt a cat or a dog. You should have advised this person to volunteer at the local shelter to find out for herself which she liked better.

Amy says: I agree that fostering before adopting is a great way to help animals and to also gain experience.

Send questions to Amy Dickinson at askamy@amydickinson.com.