Doctor’s: My doctor’s wife’s name is Clara

Doctor’: All the doctors’ files were burned in the fire.

“doctors” is used when you’re talking about more than one. So…”The doctors worked hard to save the patient.”

“doctor’s” is used when you’re talking about something belonging to one doctor. This is could be an object, idea, emotion, etc.

So…”The nurse borrowed the doctor’s stethoscope.”

doctors’ is used when you’re speaking of something belonging to more than one doctor.

So…”The cheif of staff was upset by the doctors’ strike.”

Hope that helps. There’s also a website that might help you here:

http://owl.english.purdue.edu/handouts/grammar/g_apost.html

Good luck!

doctor’s: I am envious of the doctor’s extensive education. (one doctor who “owns” or “has” an education)

doctors’: The doctors’ orders were all the same — to get bedrest. (more than one doctor who “owns” or “has” advice)

doctor’s is the possessive meaning it belongs to a single doctor….The doctor’s stethoscope was cold.

doctors’ is the plural possessive meaning it belongs to more than one doctor…..The doctors’ stethoscopes were cold.

If you say a doctor’s oath, it’s singular.

I went to the doctors’ office.

I saw many doctors.

The doctors made their rounds.

doctor’s= one doctor, possessive.

The doctor’s briefcase was ruined.

doctors’= more than one doctor, possessive.

The doctors’ luncheon was cut short by the incident.