DEAR MISS MANNERS: My wife and I have the good fortune to be co-owners of a house near the beach. When we can't use it, we often offer it to friends for the weekend or the week. This is a community where many of the houses are rented during the summer at rather high rates.

I am surprised that while our friends have thanked us (usually just an email), there has been no offer of any reciprocity beyond that, and often the thank-you seems rather perfunctory.

In particular, one close friend has stayed there five times. After her last stay, I wrote her an email suggesting that she might want to buy a small item that we could use at the house. I never received a response to that email, and I thought that perhaps the email had gone astray (it happens).

But the last time I saw her, she mentioned that it was still "at the top of her mind." Now a half-year later, we had already made that purchase, and I told her so.

I know that she, her husband, children, mother, father and aunt enjoy their time at the beach, and when we can't use the house it seems silly to have it go unoccupied. But at the same time, I feel like I have been very generous without any sign of reciprocity.

Suggestions? Or should one just realize that generosity is its own reward, and if that is not enough, stop offering?

GENTLE READER: That generosity should be its own total reward, to the extent that it is defiled by the expectation even of any acknowledgment, is an argument with which Miss Manners is only too familiar.

But she generally hears it from youngsters who are indignant that their selfish grandmothers expect them to say they received presents she sent. Instead of troubling them, why not just look to see if the checks are being cashed?

This is not an argument that charms Miss Manners, even when it is bolstered by recitals of how many other demands there are on teenagers' valuable time. She does not have far to go to find greater examples of selfishness than that of hoping to hear that one's attempts to please have been successful.

In your case, you can presume that these people like the beach house, because they keep coming back. What is lacking is any sign that they actually like you for providing it. Surely if they did, they would invite you to visit them, or otherwise exhibit gratitude (in more than a five-second email) for this enormous annual favor.

Personally, Miss Manners would be thinking warmly about strangers who pay those rather high rents. Call her selfish, but she thinks of it as saving those friends from the selfishness into which they have sunk.

DEAR MISS MANNERS: What is the best response to people I know casually and to strangers that tell me to smile?

GENTLE READER: "Say something witty that I've never heard before."

(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, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: My young children had been invited to several birthday parties where some variation of "No gifts" had been designated. I decided to take them at their word and not bring a gift.

At the door, we were met by an adorable birthday child whose little face fell as she asked my son, "Didn't you bring a gift?" while pointing to a table full of presents behind her. Everyone else had brought something anyway!

Having learned that hard lesson, I brought a small gift to the next "No gifts" party. This time all the other parents commented that the invitation had clearly stated no gifts, and I was making everyone look bad. Ack!

When the next "No gifts" invitation inevitably arrives, what do I do? My inclination is not to attend rather than continue to get it wrong.

GENTLE READER: This is exactly why Miss Manners has a rule against "No gifts" on an invitation. It plants an explicit expectation where there wasn't one. Clearly, no good can come from doing this if people are ignoring it.

If you are told "No gifts" again and decide to go to the party anyway, do as instructed. And if this meets with a disappointed child, try saying, "I'm so sorry, but your parents told me not to bring anything."

While it won't feel good in the moment to dash the hopes of an adorable (but etiquette-impaired) child, doing so may teach him two invaluable lessons: never to ask for presents -- and never to let his parents make rude requests on his behalf that they don't intend to keep.

DEAR MISS MANNERS: What is the best course of action if one is at a movie theater and someone tall enough to block your view sits in front of you?

When asked, some tall friends of mine say that they would be bothered by someone asking them to move because the person seated behind them is the one with the problem, so they should be the one to move. Other tall friends of mine say that they would consider someone getting up to move right after they sit in front of them to be more offensive because it's a passive-aggressive behavior.

Are tall folks obliged to try to avoid sitting in front of people, especially short people, if possible? Does the fullness of the theater affect these metrics at all?

GENTLE READER: Well, yes, Miss Manners would think so. If it is a practically empty theater and a tall person sits in front of a smaller one, she would consider that aggressive-aggressive behavior.

It is generally good form for a taller person to take into consideration the comfort and sight lines of others --and when it is at all possible, to try to avoid sitting in front of them. However, if they misjudge the situation and do it anyway, Miss Manners is inclined to forgive them -- but only if they agree not to get offended if the people behind them move.

(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, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.)

DEAR MISS MANNERS: My parents are taking my husband and me on an island vacation with them this summer. We haven't always had the best relationship, although things have been going well for some time now.

Could you provide some tips on how to vacation with parents and/or in-laws, what to remember and what to avoid, that might help me (and others) to contribute to the creation of a memorable experience for all?

GENTLE READER: It is all too easy to have a memorable experience when vacationing with relatives with whom you have not always gotten along. Miss Manners would have thought your goal was the opposite.

The answer to your question is: relentless good manners. That would bar any complaints, whether about the conditions of the trip or the history of the relationship, in favor of showing appreciation of this opportunity. Oh, and don't talk politics.

That may be counterintuitive in an age that considers rudeness more relaxing and therefore more appropriate to a vacation. It might also help to preserve some time for separate activities, which will be easier to do if your island destination is closer in size to Greenland than to Grenada.

DEAR MISS MANNERS: I am the president of a homeowners' association at times I write memos that require answers, but instead of answering the questions, two of our members' sister-in-laws instead let me know that I miss spelled a word.

Repeatedly I have apologized for my lack of spelling skills, but still they have to go on about how I cannot spell and I should use a dictionary because roof is not spelled roff, a simple error, they understood the content.

Is it rude to tell someone they made a mistake rather then just answer the question?

GENTLE READER: It is. Otherwise, Miss Manners would have pointed out that "misspelled" is one word, not two, it's "sisters-in-law," and that run-on sentences are exhausting.

DEAR MISS MANNERS: Is there a polite way to get away from boring people?

GENTLE READER: There are many, but application -- and effectiveness -- depends on context.

The person at a cocktail party buffet can be escaped with a simple, "Excuse me." The person on your left at a dinner party can -- after a decent interval -- be dismissed with the excuse of attending to the person on your right. (If the right-hand person is equally dull, you may have to wait for dessert.)

For spouses and other relatives, Miss Manners cautions that lasting solutions lie outside the boundaries of etiquette.

DEAR MISS MANNERS: How should I respond when a supervisor at work apologizes for being cranky?

It is nice that they apologized because they were cranky. However, I somehow feel that acknowledging that they were cranky could be an insult to them, and so simply saying "thank you" might not work toward my career goals.

GENTLE READER: Illogical as such behavior would be on the part of your supervisor, Miss Manners recognizes that you may be right. The trick is to downplay the impact of the behavior without denying its existence: "That's kind of you to apologize, but please, don't worry about it."

(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, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.)