If you wish to inquire about anything, do not do it by asking a question; but introduce the subject, and give the person an opportunity of saying as much as he finds it agreeable to impart. Do not even say, "How is your brother to-day?" but "I hope your brother is quite well."
Never ask a lady a question about anything whatever.
By all means, avoid the use of slang terms and phrases in polite company. No greater insult can be offered to polite society than to repeat the slang dictums of bar-rooms and other low places. If you are willing to have it known that you are familiar with such company yourself, you have no right to treat a party of ladies and gentlemen as though they were, too.
Avoid the habit of employing French words in English conversation; it is extremely bad taste to be always using such expressions as ci-devant, soi-disant, en masse, couleur de rose, etc. Do not salute your acquaintances with bon jour, nor reply to every proposition, volontiers. In society, avoid having those peculiar preferences for some subjects which are vulgarly denominated "hobby-horses." They make your company a bore to all your friends; and some kind-hearted creature will take advantage of them and trot you, for the amusement of the company. Every attempt to obtrude on a company subjects either to which they are indifferent, or of which they are ignorant, is in bad taste.
"Man should be taught as though you taught him not,
And things unknown proposed as things forgot."
A man is quite sure to show his good or bad breeding the instant he opens his mouth to talk in company. If he is a gentleman he starts no subject of conversation that can possibly be displeasing to any person present. The ground is common to all, and no one has a right to monopolize any part of it for his own particular opinions, in politics or religion. No one is there to make proselytes, but every one has been invited, to be agreeable and to please.
He who knows the world, will not be too bashful. He who knows himself, will not be impudent.
Do not endeavor to shine in all companies. Leave room for your hearers to imagine something within you beyond all you have said. And remember, the more you are praised, the more you will be envied.
There is no surer sign of vulgarity than the perpetual boasting of the fine things you have at home. If you speak of your silver, of your jewels, of your costly apparel, it will be taken for a sign that you are either lying, or that you were, not long ago, somebody's washerwoman, and cannot forget to be reminding everybody that you are not so now.
You need not tell all the truth, unless to those who have a right to know it all. But let all you tell be truth.