phrase,one or more than one word; and the word,one or more than one morpheme. The sentence is the highest rank of grammatical unit while the morpheme is the minimum or the lowest rank.A full sentence can generally be segmented rank by rank down to its smallest constituents---the morphemes. For example: 2 2 phrase, one or more than one word; and the word, one or more than one morpheme. The sentence is the highest rank of grammatical unit while the morpheme is the minimum or the lowest rank. A full sentence can generally be segmented rank by rank down to its smallest constituents--- the morphemes. For example: