Question: what is the difference between concrete and common nouns?
Answer: A common noun is a word that describes a type of object or concept(1) (e.g. police, town, train, emotions, etc.), as opposed to proper nouns (e.g. Lincoln). A concrete noun is something one can physically observe (dirt, air, stars, etc.), as opposed to abstract nouns (e.g. love, hate, etc.)( 2).