A concrete noun is a noun that names something that can be seen. Any object, any building, any person, anything that is physically present in the world is a concrete noun.
Here are some examples of concrete nouns:
dog, cat, house, box, book, school, grass, sky, car, person, brick, pencil, fork, grill, garage, sink, paper, nose.
Any noun that names something visible in our world is a concrete noun.
▶It’s your turn. Make a list of five concrete nouns you can see from where you are sitting right now. That wasn’t too hard, was it?