When you’re explaining foster care to a child, make sure you talk at an age-appropriate level. As you’re getting ready for your first foster placement, you can say, “You know how we get a babysitter for you when we go out? Some children need a babysitter for longer than a few hours. It might be days and days, because their families have big problems. All families have little problems from time to time, but these families have BIG problems. We’re going to babysit one of these kids, and, when everything is OK, he will go home. We will miss him, but our family—Mom Dad, you, our cat—are staying. You are in our family until you are 100.” (For a five-year-old, this is easier to understand than “forever.”)
If you will be fostering with the possibility of adopting, you don’t need to mention that, because the process is too confusing for a young child. If a child you’re fostering enters permanent custody, and you decide to adopt, you can explain it at that time.