1. Morpheme
A morpheme is the smallest unit of language that carries meaning. A word consists of one or more morphemes. For example, elephant is a morpheme, the plural suffix –s is a morpheme, the word elephants is a word consisting of two morphemes.
Morphemes can be “free”, meaning they are used by themselves, (e.g. house, car, walk, eat, from, to, but, him) or they are “bound”, meaning they only appear when attached to another free morpheme (e.g. the plural suffix –s, the past tense –ed, the prefix re-, the possessive ‘s, etc.). The concept of a morpheme is extremely useful in describing any language, and I’ll make use of it throughout this post.