|Possessive nouns are used to indicate ownership.|
Possessive nouns usually are formed by adding an apostrophe (') and s.
Which of the following is not correct?
1)Dr. Hunts has a new computer.
2)Dr. Hunts's new computer is working well.
3)Dr. Hunts' computer is new.
Both 2 and 3 are the correct answers. In your writing, you should be consistent. If you choose to leave the final 's' out, then leave it out throughout your writing.