2. If I only talk to my wife about another person, and some of the words I use are defamatory, will I be liable for publishing defamatory matter about the other person?

Communication of defamatory matter by a person to his/her spouse does not constitute a publication under the law of defamation because for this purpose a husband and wife are treated as one person ( Gatley on Libel and Slander [10 th Edition] ). In reply to the subject question, you have not published the defamatory words to a third party and therefore you would not be liable for defamation.