The plural of Post Office is Post Offices.
The plural form is offices.
Offices.
The plural form of the noun office is offices.The plural possessive form is offices'.Example: All of our offices' decor is the same using the company colors.
The plural of studio is studios, e.g. There were many studios in the office.
School offices.
post offices
The plural form of the noun post office is post offices.The plural possessive form is post offices'.Example: All of the post offices' hours are posted on their doors.
Post Offices
singular because it's talking about only one office
The plural form of post office is post offices.
The plural possessive form of postman is postmen's.