To indicate possession in English, you will use either the preposition of or the -'s form. The latter is used much more frequently in informal English.

–This is the office of the attorney.
–>This is the attorney's office.

–Here is the desk of Mr. Young.
–>Here is Mr. Young's desk.

–I know the family of Mrs. Jones.
–>I know Mrs. Jones's family.

Note the change in word order when the -'s form is used. The owner is listed first, followed by the thing owned.

Examples of Possessives

• I'll need one month's rent as a deposit as soon as possible.
• I'm having all my mail forwarded to my attorney's office while I'm out of town.