Slang: an "evil" fact of language. Coarse of profane language should never be excused, but other slang is so commonplace that it has become part of our language. But as with many things, it is all about how you say it. Basically, according to Mrs. Post, slang, in order to be acceptable, should be "fresh and applicable"
Little fact I am sure you didn't know: Emily Post was learned in diction. Not just diction, but accents. Her section on the accent is really an interesting read, and her depiction of territorial accents was pretty spot. Her best advice regarding accents can be boiled down to 2 rules: #1: if you are going to mimic the London/English accent, you should not do so with single words, but with your entire speech patterns. #2: One should not adopt french words into one's speech, but in the case of a french word becoming adopted into Americanized speech (like bouquet, chauffeur, garage, menu, etc), the very least we need to do is pronouce it correctly. My favorite example is vaudeville - which is properly pronounced as voad-veal. Who knew?? She also has the very opinionated belief that if we can not spell the word with our alphabet, we should not use it. So, anything with a little accent over the top, or something like that, is out. Granted, this effects more words than you know, but it makes sense. However, where would we be without words like bouillon, bon-bon, lingerie, and ensemble?
Overall, advice from Emily Post: in order be a charming speaker is having a pleasing voice. Not sure you have one? Her suggestion: singing lessons, even if you can't sing, there is nothing better than singing to teach you how to breath, etc. She is also of the very firm opinion that we, as a nation, do not talk too fast as much as we talk too loud. Which wonderfully is our stereotype. The harshest bit of truth about speech is that a person who has to search for words is not interesting. So, those of us who have problems with vocal expression, need to work on that.
*Read; read quality works - there is nothing better to help a person improve thier speech and vocabulary as much as reading.
*Use your dictionary! look up words that you don't know 100%.
Now that we know how to talk, next we will learn the dos and don'ts of prolonged talking with other people: conversations. This should be interesting and useful. Especially for a blunderbuss like me!