What is the purpose of visiting someone's grave, and do they hear us if we speak to them?

So the deceased when you visit them at the graveyard, they recognize who you are and they respond to your salaam. This is a hadith which is collected by Ibn Abd al-Barr from the Prophet where he mentioned this. So it is always recommended to go there to give salaam and to make dua for them. That's the key point that you make dua because dua we know as per the hadith in Sahih Muslim, it is something that can benefit the deceased. And the second point is for ourselves as a reminder as to where we will end up, where we will go. And that's why the Prophet said, "Zuru," he said, "Go and visit the graveyards because it will be a reminder of our state in terms of what we all have to go through." And if there was somebody who would have been protected from dying from the grave, it would have been the Prophet, but even he had to go through that process.