Q: My son-in-law will soon receive a Ph.D. What’s the correct way to address him when I send him a letter or card? What about when I write to both him and my daughter? And do I introduce him as “…my son-in-law, Dr. John Smith”?
A: A doctorate degree is usually used professionally (either as John Smith, Ph.D., or Dr. John Smith) but often not socially, so ask your son-in-law what he prefers. When in doubt, it’s never wrong to acknowledge the degree. If you wish to do so, address your son-in-law as “Dr. John Smith.” When addressing both him and your daughter, write “Dr. and Mrs. John Smith.” You may introduce him as “Dr. John Smith.”