DEAR MISS MANNERS: Lately I have noticed an increase in people saying “I appreciate you” instead of “Thank you” or “I appreciate it.”

I really don’t like it. I hear it fairly often from a co-worker, and I think she is sincere, so I just say “Thank you.”

That feels wrong, however. If I just went out of my way to help her, shouldn’t she say “Thank you” so I can say “You’re welcome”?

The other night at the theater, the people next to me were trying to figure out if the number on the shared armrest meant the seat to the left or to the right. I helped them out and got “I appreciate you,” which they certainly do not. They don’t know me at all.

GENTLE READER: Neither does Miss Manners, but she advises you to take a deep breath and relax.

Yes, it is a simple exchange: “Thank you”; “You’re welcome.” It had been drummed into everyone at those earliest birthday parties (“Say 'thank you,' dear”; “Now you say 'you’re welcome’”) to the point where it came out automatically.

Or so we thought.

Then people started replying to "thanks" with “no problem,” which (somewhat ironically) created a problem for many who were jarred by the change. Miss Manners is kept busy explaining that dismissing the act that inspired thanks is standard in many languages.

And now you are hearing “I appreciate you” replacing “thank you,” and you find it upsetting.

Truthfully, Miss Manners sympathizes; the change seems pointless. Why fool around with a convention that everyone understood and practiced? Yet language does change, and it is futile to expect otherwise.

You know perfectly well what was meant by “I appreciate you.” If it had been phrased as “I appreciate your taking the trouble to help me,” you might even have thought it graceful. Try just smiling in reply, and then watching the stage.

DEAR MISS MANNERS: I am curious about your thoughts on a “money dance” at a wedding reception.

The DJ will announce the dance, in which the bride and/or groom take to the floor and dance with guests at the reception -- if the person brings them money. It seems common practice.

GENTLE READER: Renting out the bride (or bridegroom), even for short periods, does not strike Miss Manners as festive. Surely she is not the only one to think how much more money could be made on longer-term rentals.

DEAR MISS MANNERS: My retired mom lives across the country and occasionally stays with my family for extended visits, often over a month. When my family is invited to an event while she is here, I hate to exclude her, but struggle to come up with a polite way to mention to our potential hosts that our party may be one more than they expected.

Do you have different advice depending on whether it is a casual gathering or a more formal event?

GENTLE READER: Here is the script for any invitation:

You: We’d love to, but my mother is staying with us, and I hate to leave her alone.

Host, option 1: Please bring her. We’d love to meet her.

Host, option 2: Sorry, another time, then.

(Please send your questions to Miss Manners at her website, www.missmanners.com; to her email, dearmissmanners@gmail.com; or through postal mail to Miss Manners, Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: My best friend and I frequently get together for lunch at local restaurants. I am sometimes embarrassed by what my friend says to servers, and I don’t know how I can get her to stop.

If the service is good, she is very effusive with her praise, and ties up the server by chatting as if they were now BFFs. If she thinks the service is subpar, she proceeds to instruct the server on how to do better in the future. Mind you, she has never worked in a restaurant.

One time we had a young waiter who was in training, and my friend was telling him how to stack up the plates as he cleared the table. I couldn’t help myself and just blurted out, “Please stop.”

Should I ignore this from now on? What could I say to get her to realize that this is embarrassing?

GENTLE READER: If “Please stop” did not work, Miss Manners is afraid a more polite approach will not, either.

But if similarly pressed, she would say, “Let’s let these servers do their job and just enjoy one another’s company, shall we?” She would omit the part where she tells your friend that stacking plates as you remove them is improper in the first place.

DEAR MISS MANNERS: What is the appropriate way to address people who cut in line, specifically at theme parks with long lines (60+ minutes) and limited staff?

My family was recently at a large, well-attended theme park, and had multiple encounters with individuals cutting in line. Half of our group felt it was fine to block the line cutters and prevent them from continuing, while the other half felt that doing so was disruptive to other guests and not worth the aggravation.

Given that there were no theme park workers in sight to address the problem, what would you suggest?

GENTLE READER: “Excuse me, but there is a line here and the rest of us are waiting in it.” In this case, Miss Manners believes that words are more effective than (disruptive) actions.

DEAR MISS MANNERS: I have an acquaintance who has been in my home a few times, even though I’ve never invited him over. He’s shown up at my door without calling or texting, and asks to come in for tea.

He’s pleasant, and I don’t mind the company -- when I’m free. But on a recent visit, he said I should keep my home tidier if I wanted him to come over again.

I keep my house clean, but he’s shown up when I’ve been in the middle of folding laundry, for example. Or when I had some papers on the coffee table, a towel hanging to dry in the bathroom, my gym shoes beside the door and a coffee cup beside the kitchen sink.

When I’m expecting guests, I make my home look like nobody lives there. But am I really obligated to keep my home constantly spotless just in case someone drops in?

GENTLE READER: No. But you also do not have to let this person in just because he shows up at your door.

Miss Manners suggests you practice saying, “This is not a good time for me.” No reason necessary. If he presses for one, you might say, “I’m afraid my house is not up to your standards. I will be sure to invite you over when it is.”

(Please send your questions to Miss Manners at her website, www.missmanners.com; to her email, dearmissmanners@gmail.com; or through postal mail to Miss Manners, Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: I attended a live theater performance. Seated directly in front of me was a very tall woman whose hair was styled in an updo that added -- seriously -- five or six inches to her height!

I could not see the stage at all unless I leaned uncomfortably left or right, and each time she shifted in her seat, I had to shift in mine. I couldn’t imagine anything I could politely say to her about this, so I just did my best to look around her.

Does Miss Manners have any suggestions for this situation? At the very least, can she ask tall people to consider others when styling their hair for the theater?

To be fair, the venue was a former movie theater, so the seating was designed not for viewing a stage performance, but for looking at a large, high screen. I will also mention that while I did not engage with her directly, this person seemed to be very lovely in interacting with her friends.

GENTLE READER: Sure. Because she probably looked fabulous and was being widely admired by them. They did not have to sit behind her.

Miss Manners has witnessed enough awards shows to notice that extreme hair and costume choices may be photo-worthy, but they ignore the comfort of seat companions who would like to watch the performance -- or at least not get an aggressive feather in the eye while doing so.

Miss Manners admires fashion, but will remind her readers that consideration of others must be regarded when you are sharing close seating quarters. Any outsized accoutrements should at least be made removable.

DEAR MISS MANNERS: A longtime acquaintance joined us for a casual meal at our home. Eating her sandwich resulted in a scattering of crumbs on the table. I was surprised to see her hand sweep the crumbs from the table to the floor -- twice! -- while she ate. Our home is not a beer-soaked bar.

Possible choices in the future: 1. Lightly say, “Hey, those crumbs won’t clean themselves up!” 2. Say, “Excuse me while I clean up your space” as I do so, using a whisk broom. 3. Hand her a wet wipe -- “Ants, you know!” or 4. Sadly, do not invite her to our table again. Which would you suggest?

GENTLE READER: 5. “Perhaps I should get you a bigger plate. That one does not seem to be doing this messy sandwich any favors.”

DEAR MISS MANNERS: I spent considerable time shopping for just the right statement necklace to complement my fairly simple wedding dress. I thought I had made the perfect choice with a piece of costume jewelry. But at our wedding reception, a friend of my husband’s approached me and asked, “So, are those REAL diamonds?”

I was shocked by the question, but before I could think of an answer, a relative piped in with, “Of course not! If those were real diamonds, they could have afforded to have their reception in a nicer place!”

How could I have replied at that point?

GENTLE READER: “I’m so glad that both of you could be here to celebrate us.” This should be said with a beatific bridal smile -- the sincerity of which Miss Manners hopes your guests will be questioning for the rest of their rude and impertinent lives.

(Please send your questions to Miss Manners at her website, www.missmanners.com; to her email, dearmissmanners@gmail.com; or through postal mail to Miss Manners, Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106.)