Morpheme

In morpheme-based morphology, a morpheme is the smallest linguistic unit that has semantic meaning. In spoken language, morphemes are composed of phonemes, the smallest linguistically distinctive units of sound.

The concept morpheme differs from the concept word, as many morphemes cannot stand as words on their own. A morpheme is free if it can stand alone, or bound if it is used exclusively alongside a free morpheme. Its actual phonetic representation is the morph, with the morphs representing the same morpheme being grouped as its allomorphs.

The word "unbreakable" has three morphemes: "un-" (meaning not x), a bound morpheme; "-break-", a free morpheme; and "-able", a bound morpheme. "un-" is also a prefix, "-able" is a suffix. Both are affixes.

The morpheme plural-s has the morph "-s" in catsdishesdogschildren.