A child’s invented expression can reveal a distinction adults stopped noticing.

Children make up words because they have noticed something and found the available vocabulary insufficient. Often the distinction they are pointing at is real and adults have simply stopped registering it, having smoothed it into a category long ago. The invented word is a fresh observation, not an error.

When a child says something oddly precise, ask what they mean rather than correcting it. The answer is often worth having. It is also a reminder that fluency in a language includes losing some of the fine distinctions the language does not conveniently support.