It seems you are absolutely sure that dead people cannot hear or understand you, so sure that you think there can be no wiggle room.
But did you know that during the French revolution, severed heads of those executed hours ago were known to open their eyes and look at people who spoke their name?
Of course you can. But if you think they can reply, then you might have a problem.
I still talk to the mother of my children, more than 10 years after she passed. I tell her how they're doing, and I ask her questions I know she cannot answer. I am an atheist so I know that of course there is no way she can hear me, but it's not for her. It's just for me. I hear her voice in my head, guiding and advising me. Now that they are all adults and living their own lives, I don't talk to her as much as I used to, while they were younger.
I think it depends on what you are expecting out of the conversation. The chances are they will be excellent listeners. Buf that's about it unless something is wrong with them or you.
Even while people are alive, a huge proportion of our full experience of them involves expectations, assumptions, recollection, expectation…in addition to direct interaction.
Post-life, we mist remove the direct interaction, but the rest remains. Talk away!
I still talk to my dead dog sometimes. Mostly about whether or not she’d like the weather on a given day, how much she’d like our current dog, and how much I miss her.
I don’t expect replies. It’s for my own benefit more than anything.
Necromancy as a religious practice is not as rare as people would have you believe but if you hear them talk back double check with a psychiatrist that you’re doing ok