This textbook is about the structures of words and sentences. In the field of linguistics, the study of the structure of words is called morphology.

To study the structure of words, we look at their components. Let’s take the word untidy, meaning ‘not organized or clean,’ as an example. Even though untidy is a single word, we can break it up into two pieces, un- meaning ‘not,’ and tidy meaning ‘organized or clean.’ These two components are called morphemes. We define morphemes as the smallest meaningful units in language. When we break up a word into its morphemes, we say it has been segmented.

Some words are simplex, meaning they only contain a single morpheme. The word pumpkin, a kind of squash, is a simplex word. Other words are complex, meaning they contain more than one morpheme. The word untidy, as we have already seen, is complex. Another word for complex is polymorphemic.

Note that we can break up the word untidy into even smaller pieces. For example, we can break it up into consonants and vowels, which we could write in the International Phonetic Alphabet (IPA) as /ʌ n t ɑi ɾ i/. Likewise, we can break up the word pumpkin to get /p ʌ m p k ɪ n/. Although individual consonants and vowels do function as units in phonology, they are not meaningful units. Each of these individual consonants and vowels do not mean anything on their own, which is why they are not morphemes.

We can also break words up into syllables. The word untidy has three syllables, /ʌn/, /tɑi/, and /ɾi/. The sequence /ʌn/ happens to be a morpheme in this word, but the other two syllables are not. A morpheme may be one syllable long, like un-; a morpheme may be longer than a syllable, like tidy; or a morpheme may even be shorter than a syllable, like the plural marker -s in the word cats! Just like consonants and vowels, syllables are structural units of phonology that do not encode meaning.

Another possible definition of morphology is the systematic co-variation of form and meaning. In this definition, systematic means a pattern or system that is predictable or rule-governed. Co-variation means that when some element varies (in this case form), another element (meaning) varies in a predictable way at the same time. Form means the sounds or signs used to produce a word. In other words, morphology is the study of how, if you change the shape of a word, its meaning changes, too; and if you change the meaning of a word, its shape changes, as well.

Let’s consider again the morpheme un- in the word untidy. This morpheme shows up in lots of other words, as shown in Table 1. This is an example of systematic co-variation of form and meaning. In the first column, we have a set of words and their definitions. When we add un- to the beginning of each of these words, the meaning changes to mean the opposite. Adding un- is a variation in form, while adding ‘not’ to the definition is a variation in meaning. These two variations are related since the same change in form always leads to the same change in meaning, and vice versa.

On the other hand, the word pumpkin is simplex, meaning it does not have any components that exhibit a systematic co-variation in form and meaning. By coincidence, the word pumpkin is made up of two components that do show up in other words, pump and kin. On its own, pump means ‘use pressure or suction to force air or liquid to move from one contained area into another’, which has nothing to do with squash vegetables like pumpkins. Although the words pumpkin and pump share form, they do not share meaning. Their similarity is a coincidence. Likewise, the word kin, on its own, means ‘family’. Again, this has nothing to do with squash vegetables and its similarity in form to pumpkin is a coincidence. Neither pump nor kin are morphemes in the word pumpkin.

Some of the things we study in morphology include the following:

• We look at related words to identify the co-variations in meaning and form and identify morphemes.
• We classify morphemes based on their structural, functional, and meaning properties.
• We determine whether a given string of morphemes is a word or a phrase.
• We look at ways words are built or created.
• We classify words according to the words they can appear alongside, their meaning, and their structure.
• We look for common patterns in word structure and word formation across the languages of the world.
• We study how the structure of words interacts with other components of language, such as phonology.

Morphology matters because a lot of language play and creativity happens with morphology, when we build new words and modify old ones. (For a fun example, check out this article explaining the grammar of doge!) We have intuitions about the words in our native languages and other languages we speak well. We have opinions about which words are good or come out sounding more awkward, which are funny and creative, which are confusing, and which are plain and boring. But how do we know these things? And which of these patterns are particular to specific languages, and which seem to show up in all languages?

Check yourself!

References and further resources

Comedy and satirical linguistics

🎉 Wishnetsky, Susan. 2006. Morphemes: A new threat to society. Lingua Pranca. https://specgram.com/LP/26.coma.morpheme.html

For a general audience

🧠 CrashCourse. 2020. Morphology: Crash Course Linguistics #2. https://www.youtube.com/watch?v=93sK4jTGrss

🎉 McCulloch, Gretchen. 2014. A linguist explains the grammar of doge. Wow. The Toast. https://the-toast.net/2014/02/06/linguist-explains-grammar-doge-wow

For linguistics students

🔍 Anderson, Catherine and Bronwyn Bjorkman. 2020. Why we do morphology. Word to the Whys. Teaching in Linguistics Community of Practice. Podcast. https://sites.google.com/view/word-to-the-whys-podcast/home/morphology