flesl.net grammar glossary::morpheme


• Morphemes are the most fundamental grammatical units. They are at the bottom of the five-item grammatical hierarchy. Each of the other four categories, sentences, clauses, phrases, and words can be analyzed into parts which also have grammatical significance: —sentences into clauses, clauses into phrases, phrases into words and words into morphemes. But this is not possible in the case of morphemes. (Grammar is generally considered to have two branches: morphology, the study of the internal structure of words and syntax, the study of how words are arranged to form phrases, sentences and clauses.)

• For example, the word “unfriendly” contains three morphemes: “un,” “friend,” and “ly.” To take another example, the past tense form “walked” contains two morphemes “walk” and “ed.” In these examples, the morphemes, “friend,” and “walk” are “free morphemes” because they are capable of functioning as independent words. The others, “un,” “ly,” and “ed” are known as “bound morphemes” because they cannot be used as independent words.

• Although they cannot be used as independent words, bound morphemes are meaningful because they change the meaning of the free morphemes to which they are attached. For example, when “ly” is added to “friend,” the basic meaning of the word is changed and it comes to mean “acting like a friend”; and when the second bound morpheme “un” is added, the meaning changes again and comes to be “not acting in a friendly way.”
• When a free morpheme is used independently—without any bound morphemes attached—it is, of course, also a word. This is a case of unitary constituency. A unitary constituent is a grammatical element which contains only one item from the next, lower, category in the grammatical hierarchy, for example, a sentence containing only one clause, a phrase containing only one word, or as in this case, a word containing only one morpheme.

• There are two types of bound morphemes: “inflectional” and “derivational.” Inflectional morphemes are used to create words that are grammatically correct in a particular context. For example, the rules of grammar require that an -s morpheme be added to plural nouns and that the -ing morpheme be added to a verb to give it a “continuous” sense. Derivational morphemes, are added to the beginning of free morphemes (“prefixes”) or to the end (“suffixes”) to create words that have a similar but contrasting meaning or that have a similar meaning but which belong to a different word class. (For example, “re” + “read” to make a word meaning “read again,” or “deaf” + “ness” to change an adjective into a noun.)

• Although a particular bound morpheme will always have the same significance (i.e. the same effect on a word’s grammatical appropriateness, its word class, or its dictionary meaning) its pronunciation can vary depending on the phonetic quality of the word to which it is attached. The past tense morpheme, “-ed,” for example, is pronounced in three different ways: as [ɪd] after a verb that ends in [d] or [t], as [t] after a verb that ends in an unvoiced consonant, and as [d] after a verb that ends in a voiced consonant.