Hello Kathy, it sounds very hard. Has their been a family pet that Liam has seen die? Or a wild animal? Sometimes a pet mouse or goldfish can be a way of seeing it and understanding, burying it and being sad. The way kids understand stuff like that is so basic. It can be a way of going through the process of understanding what death is.

He's very young so maybe he's just not old eough to fully grasp it yet? The way he is understanding it eg. he's gone away, is quite logical really. Maybe you could look into story books aimed at young children on the subject? Maybe that would be another way of helping him understand?