In morpheme-based morphology, a morpheme's the smallest linguistic unit that's semantic meaning.In spoken language, morphemes are composed of phonemes (the smallest linguistically distinctive units of sound), and in written language morphemes are composed of graphemes (the smallest units of written language). The concept morpheme differs from the concept word, as many morphemes can't stand as words on their own. A morpheme's free if it can stand alone, or bound if it's used exclusively alongsid… (More on Morphemes)