Americannames are written and spoken with the given name first and the family namelast. So John Smith‘s family name is Smith, not John.
In aformal setting, address men as "Mister" (abbreviated as"Mr."), married women as "Misses" (abbreviated as"Mrs."), and unmarried women as "Miss" (abbreviated as"Ms."). These days many women prefer to be addressed using theabbreviations "Ms." or "M.", pronounced "miz". Ifthe person has an M.D. or Ph.D., they will often be addressed as"Doctor" (abbreviated as "Dr."). Faculty are addressed as"Professor" (abbreviated as "Prof.").
Inan informal situation, Americans will introduce each other by first name,without titles, and occasionally by just the last name. If you are introducedto somebody by first name, you can address him or her by first name the nexttime you meet. The only exception would be for someone who holds an importantposition, such as the university president or provost. Unless they tell you otherwise,faculty should be addressed using their title and last name (e.g.,"Professor Smith").
Whenin doubt, use the formal manner of address, since it is better to err on theside of formality. It is also appropriate to ask how they prefer to be addressed.
Childrenshould always address adults in the formal fashion, using their title and lastname.
From: www.eduPASS.org