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 ...