Never discourse upon your ailments.
Never use words of the meaning or pronunciation of which you are uncertain.
Avoid discussing your own or other people's domestic concerns.
Never prompt a slow speaker, as if you had all the ability. In conversing with a foreigner who may be learning our language, it is excusable to help him in some delicate way.
Never give advice unasked.
Do not manifest impatience.
Do not interrupt another when speaking.
Do not find fault, though you may gently criticise.
Do not appear to notice inaccuracies of speech in others.
Do not always commence a conversation by allusion to the weather.