Strictly speaking, the distinction between concrete noun and abstract noun is not really a matter of grammar, but of semantics. In other words, the decision to label a noun as concrete or abstract is more to do with the word’s meaning than its grammatical form or function.
There is very little, if any, grammatical difference between the ways in which abstract and concrete nouns operate.
However, we are including these categories here because so many English courses make reference to them and because they can help to make sense of meaning in some texts.
How are these categories defined?
Of course, these are often rather subjective judgements which could be argued about. Does concrete mean tangible? Are sounds concrete? Is light concrete? We can see it, and it appears to be ‘out there’, but does it actually occupy physical space? Linguists disagree about these categories. The important thing is to be aware of the difficulties.