Here's a more accurate way to think about it:
Morphemes are the smallest units of meaning in a language.
While it's true they can't be broken down into smaller meaningful units, the emphasis is on meaning, not just "signs."
Here's why:
* Meaningful vs. Sign: A morpheme might be represented by a single sound or a group of sounds, but that's not its defining characteristic. Its core function is to convey meaning.
* Example: "un-", "happy", and "-ness" are all morphemes. Each contributes a specific meaning: "not" (un-), "joyful" (happy), and "state of being" (-ness).
Think of it this way:
* Words: Are made up of morphemes.
* Morphemes: Are the building blocks of words, carrying meaning.
Let me know if you'd like more examples or want to explore different types of morphemes!