Probem when trying to create a coroutine

I am trying to create a coroutine, but for some reason visual studio doesn’t like it, can somebody help me:

public IEnumerator RespawnPlayerCo()
{

    Instantiate(deathParticle, player.transform.position, player.transform.rotation);
    player.transform.position = currentCheckPoint.transform.position;
    player.GetComponent<Rigidbody2D>().velocity = Vector3.zero;
    Instantiate(respawnParticle, player.transform.position, player.transform.rotation);

} 

It doesn’t like the part where it says “RespawnPlayerCo” it says that not all code paths return a value.

A CoRoutine must implement at least one yield statement.

You can do the following :

public IEnumerator RespawnPlayerCo()
{
     Instantiate(deathParticle, player.transform.position, player.transform.rotation);
     player.transform.position = currentCheckPoint.transform.position;
     player.GetComponent<Rigidbody2D>().velocity = Vector3.zero;
     Instantiate(respawnParticle, player.transform.position, player.transform.rotation);
    yield return true; // or
    yield return new WaitForSeconds (1f);
}