Chris' office or Chris's office

Answer 1

There are two accepted forms for possessive singular nouns ending in s:

Add an apostrophe (') after the existing s at the end of the word: Chris' office

Add an apostrophe s ('s) after the existing s at the end of the word: Chris's office

Examples:

You'll find Chris' office in the sales department.

You'll find Chris's office in the sales department.

Note: The -s's is the most commonly used form, but if you are a student, use the form that is preferred by your teacher.