I know that the sentence "David or Michael forgot to take his parasol" is correct.
But what about the case when two opposite genders are connected by or?
David or Alice forgot to take _ parasol.
Which pronoun fits the blank?
Likewise when or connects plural and singular nouns. E.g., "either the manager or his assistants failed in their duty" is fine, but what if I switch them around?
Either the assistants or their manager failed in _ duty.
Again, which pronoun should be used here?