The lowest level is that that of a word
The lowest level is that that of a word. Words too can often be broken down further into meaningful parts referred to as morphemes. A morpheme is the smallest meaningful unit of language. For example, the words ‘repainted’ and ‘tables’ can be broken into parts: re-paint-ed and table-s.
In the word ‘re-paint-ed’, the part ‘re-‘ means ‘to do again’, the part ‘-paint-‘ means ‘to apply color’ and the part ‘-ed’ means ‘in the past’. These meaningful words of a word are called morphemes.
In the word ‘table-s’ we see that the meaning of morphemes may be concrete as in morpheme ‘table-‘ which means ‘a flat slab fixed on legs’. The meaning may also be grammatical as in the morpheme ‘-s’ which means ‘plural’.
Though morphemes are constituents of words, not all words break into parts and therefore words may be made up of only one morpheme. See sentence (4) repeated below, where only three of the words can be further broken down into more than one morpheme. All the rest of the words have only one morpheme.