b) Structurally morphemes fall into three types: free morphemes, bound morphemes, semi-free (semi- bound) morphemes.
A free morpheme is defined as one that coincides with the stem 2 or a word-form. A great many root-morphemes are free morphemes, for example, the root-morpheme friend — of the noun friendship is naturally qualified as a free morpheme because it coincides with one of the forms of the noun friend.
A bound morpheme occurs only as a constituent part of a word. Affixes are, naturally, bound morphemes, for they always make part of a word, e.g. the suffixes -ness, -ship, -ise (-ize),etc., the prefixes un-,
1 See ‘Semasiology’, §§ 13-16, pp. 23-25. 2 See ‘Word-Structure’, § 8, p. 97.
