My grandma died and we want to know how you can talk to them.

I lost both my parents 10 years ago, and I talk to them all the time. They don't answer, but I will stand by their urn and tell them how things are going, how the kids are, how I am, all the things I'm happy about or upset about.

Just talk to her. I'm sure she's listening. :)

I often go out in the evening and "talk" to my ex wives who have passed on ahead of me. They of course can not talk back, but I know somehow they hear me.

You can also just rest assured she lived a full life. Why the need for contact?