“The right way to look at single inheritance is as a specialization of composition. Like all specializations, it does less. It is more specific. Whenever you declare that Child IS-A Person, the compiler writes “Child HAS-A Person” and “Child BEHAVES-LIKE-A Person” and “Child DELEGATES-TO Person” for you. When this is exactly what you mean to accomplish, it is useful: it expresses your intent clearly to other programmers.

When single inheritance is not exactly what you mean to express, use the more general purpose, flexible tool: composition.