Apostrophe for Understood Possessive
The Apostrophe
Rulebase Summary
Use the apostrophe and s for a possessive that is understood but not completed — where the thing possessed is implied rather than stated.
Examples
A. I bought it at the doctor office — I mean at the doctor.
A. I bought it at the doctor's.
The word 'office' is implied — the apostrophe and s still mark the possessive even though the possessed noun is unstated.
A. We spent the evening at my grandmother.
A. We spent the evening at my grandmother's.
The thing possessed (house, place) is implied — the possessive form is still required.
Transcript Notes
Use the apostrophe and s for a possessive that is understood but not actually completed in the sentence. The possessed noun may be implied from context (I patronized App Pharmacy for years. I also sent a lot of my friends to App's. — meaning App's pharmacy). His work was every bit as specialized as the technician's — meaning the technician's work.
Style Guide References (2)
Morson's
BGGP