Why am I getting "The modifier 'virtual' is not valid for this item" error?

I'm trying to create mvc application with model below: (the code is large. I think it will be more understandable for you)

public class Job
{
    public int JobId { get; set; }
    public string Name { get; set; }

    public List<Job> GetJobs()
    {
        List<Job> jobsList = new List<Job>();
        jobsList.Add(new Job { JobId = 1, Name = "Operator" });
        jobsList.Add(new Job { JobId = 2, Name = "Performer" });
        jobsList.Add(new Job { JobId = 3, Name = "Head" });
        return jobsList;
    }
}

public class Person
{
    public virtual int PersonId { get; set; }
    public string FullName { get; set; }
    public int JobId { get; set; }
    public virtual Job Job;
    public string Phone { get; set; }
    public string Address { get; set; }
    public string Passport { get; set; }
    [DataType(DataType.MultilineText)]
    public string Comments { get; set; }
}

public class PersonPaidTo : Person
{
    [Key]
    public override int PersonId { get; set; }
    public virtual List<Order> Orders { get; set; }
}

public class Head : Person
{
    [Key]
    public override int PersonId { get; set; }
    public Job Job { get; set; }
    public Head()
    {
        Job.Id = 3;
    }
}

I have an error in class Person in the field Job:

The modifier 'virtual' is not valid for this item