Rule 20: Phrase or name combinations.

Examples

Miller and Keane's reference

physician-in-chief's office

counselor-at-law's profile

Rule 21: Preceding a gerund

Use the possessive form of a noun or pronoun modifying a gerund.

Examples

Correct: We are concerned by the patient's taking so long to respond to treatment.

not

We are concerned by the patient taking so long to respond to treatment.

Rule 22: Preceding a gerund

Watch for subtle but important variations in meaning created by the use (or non-use) of the possessive form preceding the -ing form of a verb.

Examples

The patient was not injured, thanks to the nurse's preventing her fall.

The patient was not injured, thanks to the nurse preventing her fall.

(emphasis placed on thanking the nurse, not the nurse's action)