Mister and Missus, known by the abbreviations Mr. and Mrs. , are the correct ways to address men and women, according to history and etiquette. Using their full names is considered appropriate only in very formal situations. There are three ways to spell Mister: Mizzer, Miszzer and Mizzeer. The first one is used primarily in old literature while the other two are found more recently. Mizzeer is based on the Mizrahic language spoken in Israel and is pronounced like "meez-eer". There is no specific reason for using this spelling instead of the others. Missus is the female form of Mister. It is used when speaking of a man who is not your husband or boyfriend. A woman should use Mr. if she is not married. Otherwise, she should use Miss or Ma'am. For example, if you want to say that someone is an MRS. , then you should use the abbreviation. However, if you need to refer to her as a lady rather than a wife, you should use Miss or Ma'am instead. Some people may take offense if you use their title instead of their full name.