var query =    people.GroupJoin(pets,                     person => person,                     pet => pet.Owner,                     (person, petCollection) =>                        new { OwnerName = person.Name,                              Pet = PetCollection.Select( p => p.Name )                                                 .DefaultIfEmpty() }                    ).ToList();

var query = (from person in context.People             join pet in context.Pets on person equals pet.Owner             into tempPets             from pets in tempPets.DefaultIfEmpty()             select new { OwnerName = person.Name, Pet = pets.Name })            .ToList();