Whose is this?
这是谁的？
To whom does this belong?
这是谁的？

Belong+某个地方
Where do these spoons belong？
这些勺子应该放哪儿?

Belong +某人
This book belongs to Elizabeth.
这本书是伊丽莎白的。
Tom! You're 8 years old now! You shouldn't take what doesn't belong to you.
你已经八岁了！你不应该拿不属于你的东西！

Belongings
所有物
How do I get my children to pick up their belongings?
我怎么才能让孩子们收好自己的东西呢？
Personal belongings
属于个人的东西。