Many children associate objects with ideas before they start to talk. In schools, objects are often used to help children understand their timetable, and to anticipate what is going to happen during the day. Using objects in this way is called Objects of Reference. If your child has limited understanding or doesn't use speech at all, you could use objects to talk about events, activities and choices.
For example, you can use a cup to show that a drink is coming, or a nappy to show that it's time for a nappy change. If you put together a small tray of objects like this, your child can use it to ask for a drink, tell you that they're hungry or tired, or want to do a favourite activity.