English has a few suffixes that can make abstract nouns out of adjectives: There’s the relatively rare –cy, which turns fluent into fluency and idiot into idiocy. There’s the more common –ty or –ity ...

Think about concrete for a second -- even if you weren’t already thinking about it. Can you picture it? Can you feel its hardness? Do you see a driveway, sidewalk, or building in your mind? Concrete ...

When we use an abstract uncountable noun to make a general statement, we don’t use the. When we use an abstract uncountable noun to refer to a specific example of a noun, we use the before the noun.

English has a few suffixes that can make abstract nouns out of adjectives. There's the relatively rare –cy, which turns fluent into fluency and idiot into idiocy, and there's the more common –ty or ...