compound possession: shared and individual ownership
Marking the possessive when two or more names own something.
When two or more people own one thing together, only the final name takes the possessive: Dana and Lee’s office. When each person owns a separate thing, every name takes the possessive: Dana’s and Lee’s offices.
Examples
UseDana and Lee’s lease runs out in May. (one lease two people share)
UseAna, Ben, and Cole’s boat needs a new motor. (one boat three people share)
UseDana’s and Lee’s cars are in the shop. (each person owns a car)
AvoidDana’s and Lee’s lease runs out in May. (if the two share one lease, only the final name takes the possessive)