Yes, it can. The object will need to inherit from both Subject and Observer classes. If this is the case, we may need to deal with loop.

You can also Combine the Subject and Observer classes. In Smalltalk, the Subject and Observer interfaces are defined in the base class Object. Like Smalltalk, class libraries written in languages that don't support multiple inheritance don't define separate Subject and Observer classes but combine their interfaces in one class so an object can act as both a subject and an observer without multiple inheritance.