affix
【正确答案】：Affix refers to the morpheme that cannot be used independently by itself,but has to combine with other morphemes to form word, such as inflectional and derivational morphemes. For example, -(e)s indicating plurality of nouns and-'s indicating the possessive case of nouns are inflectional morphemes, while -less and -ness in the word carelessness are derivational morphemes.
(P52)：词缀不能单独使用,必须和其他词素组成一个词。它包括屈折词素和派生词素。
