How can an actor be in more than one class?

Take MySupplier for example, they are a supplier, so they are in the class 'suppliers’
They are also potential partners and so are in a subclass of partners

How can an actor be in both classes?

When does an actor become a class?

If MySupplier is an actor and also in the class ‘suppliers’ what notation should be used to denote that this actor is in a class?
Or should I not referred to MySupplier as an actor but as a member of a class? What notation indicates a member of a class? Is it the instance of the class or as previously stated an actor considered part of a class.

Thanks if at all my question is clear.

Hi mlewis,

I’m not completely sure to understand what you mean, I apologize in advance if I not.

In UML 2.x actors are no more classes; if you try to draw an association using VP between a class and an actor a “forbidden” sign is displayed on the mouse position. Which is the meaning of this?
The meaning is simple: actors and class have completely different meanings and field of application. I think that you should do a “mental” jump about actors. You should think to them not as class but as roles. An actor is “something” that is using your system to reach some goal, this means that an actor is outside your system boundaries so trying to represent it inside makes no sense at all.
Check if supplier and/or partner are really identifying a role. Maybe all you need is an actor named “registered user” doing something (a use case) with the system to get a business result. If they really use the system in different ways then you will need two actors.
On the other hand (inside the system) you could have an internal representation of the actors (i.e. two classes) with the same name of the actors outside the system itself. This is not forbidden.

Hope it helps.