A pronoun that modifies a gerund or a gerund phrase should appear in the possessive case (my, our, your, his, her, its, their).
Your modifies the gerund phrase being hit by lightning.
A noun that modifies a gerund or gerund phrase also must be in the possessive case: victim’s, birds’.
The possessive noun aristocracy’s modifies the gerund phrase exploiting the lower classes.
Exercise: Pronoun case (such as I vs. me) 1
Exercise: Pronoun case (such as I vs. me) 2
Exercise: Pronoun case (such as I vs. me) 3
Exercise: Pronoun case: review 1
Exercise: Pronoun case: review 2
Related topic:
Possessive case of nouns
gerund A verb form ending in -ing and used as a noun: typing, thinking.
gerund phrase A gerund (-ing verb form used as a noun) and its objects, complements, or modifiers: typing my résumé, thinking about the future.