What to Say to Someone Who is Grieving

I mentioned to a friend that, after receiving notification of my mate's death, few people from a certain online group sent an acknowledgement, and she said perhaps it was because they did not know what to say. This is probably true. Most comments posted to me on the various threads began with: "I don't know what to say."  Of course, being writers, these people followed that statement with very touching responses, but I also received touching remarks from non-writers. To be honest, all...