What I mean is that 2 people on the island can talk to the dead Hurley and
Miles but they do it in 2 different ways because Hurley can have conversations with the dead but Miles can only here how they died and who they were befor they died Hurley has talked to people such as
-Charlie
-Mr. Eko(he was playing Ches with him)
-he thought jacob was dead but no
-Dave he is probably dead because he can talk to him but everybody says hes not there same with every body dead he sees
Hurley said when Jacob visited him in the taxi "you must be dead" Jacob tells him hes not and that he has to go back to the island witch I think is why he wanted Jack to go back to the island.There was also a guitar in the seet that Jacob was siting next to Hurley says "you forgot your guitar"
Jcob says "its not mine" and the guitar looked like charlies guitar and Jacob was reminding Hurley about Charlie and the island so the he will go back or maybe dead Charlie was in there befor that moment.

We first see that Miles can talk to the dead in the episode some like it hoth were it starts as miles as a boy with his mother and a other man when he heres a man he follows the noise until he gets to a room with a dead man in it little Mile gos crazy because he can here him the man says he has been dead for years but Miles can still here him.Miles grows up and becomes a person who talks to the dead one day he visits a man he pretend to talk to his dead son but he lies. Miles can only talk to the dead if he has the dead body but he can talk to the dead only if he wants to and Miles can't see the dead but Hurley can. Hurley sometimes dosn't want the dead to be there but they apear there anyway.
Miles was invited to the island by the frater people most likely becuse he can talk to the not living they ofered him over 1 million dollers and right after this moment miles was kidnaped by the same man that was on the island he asked Miles "what lies in the shadow of the statue?" the same thing that they asked Richard about and he said somthing I can't understand.

on the island the Dharma man was killed in the orcid station by one of his fillings comeing out and going through his head Miles asked his dead body what happend.Miles also talked to the dead when he fowned daniel ruso beridde under ground wich was a clue that he can talk to the dead but we did not compleetly know that.