insert data to multiple table in same time

i try with this :

Employee emp = new Employee();
emp.Name = form["Name"].ToString();
emp.Salary =Convert.ToInt32(form["Salary"]);
emp.Email = form["Email"].ToString();
emp.DistrictId = Convert.ToInt32(form["DistrictId"]);

var coursesId = form["Courses"];

string[] coursesIds = null;

if (coursesId != null)
{
coursesIds = coursesId.Split(',');
}

List courses = new List();

foreach (var item in coursesIds)
{
Empcourse ecour = new Empcourse();
ecour.EmployeeId = emp.Id;
ecour.CourseId = Convert.ToInt32(item);
courses.Add(ecour);
}
// emp.EmployeeCourses=courses
emp.EmployeeCourses=courses;
db.Employees.Add(emp);
db.SaveChanges();

but i face problem in this line

emp.EmployeeCourses=courses;

how to assign list to object

it give me this error

cannot implicity convert convert System.collection.Generic.list to System.collection.Generic.Icollection

can you help me

what i need actually insert

Save the following data

Name,Email,Salary,DistrictId in table Employee

EmployeeId,CourseId in table EmployeeCourse

EmployeeId,LanaguageId,LevelId in table EmployeeLangage

and write it in Create

http post

[HttpPost] 

public ActionResult Create(Customemployee cemp) 

{ r

eturn View();

 }