Answer:
The abstract noun is dreams and the concrete noun is Uncle Joe.
Step-by-step explanation:
An abstract noun isn't physically there; in other words, it isn't an object. On the other hand, a concrete noun is a noun that can be experienced with one or more of the five senses (see, hear, touch, smell, and taste). You can't experience dreams with any of the five senses, but with Uncle Joe, you can since he's a physical human being.