Morphology: the structure of words

Inside the word

A fluent speaker who meets the new word unfriendable knows at once what it means and that it is an adjective, though no dictionary taught it. The speaker knows the pieces (un-, friend, -able) and the rules for putting them together. Morphology is the study of those pieces and rules: the internal structure of words.

1. The morpheme

A morpheme is the smallest unit that has a meaning or a grammatical job. It is not the same as a syllable: elephant has three syllables but one morpheme, while cats has one syllable and two morphemes (cat + plural -s).

2. Free and bound morphemes

A free morpheme can stand alone as a word: book, happy, run, the. A bound morpheme cannot: -s, -ed, un-, re-, -ness.

• Free morphemes are either lexical (content words that carry most of the meaning: nouns, verbs, adjectives, adverbs) or functional (grammatical words: articles, prepositions, conjunctions, pronouns, such as the, of, and, it).
• Some roots are bound. The -ceive of receive, deceive, perceive and the -mit of permit, submit, commit recur with a common core, yet never stand alone. Cran- in cranberry is a bound root that occurs in a single word; such pieces are called cranberry morphemes.

3. Roots, bases and affixes

The root is the core that carries the main meaning and cannot be broken down further: act in reactivation. A base is any form an affix is added to: active is the base of activate, and reactivate is the base of reactivation. The stem is the form that inflections attach to: worker is the stem of workers.

Affixes are bound morphemes classified by where they attach.

• Prefix – before the base: un-kind, re-write, pre-view.
• Suffix – after the base: kind-ness, teach-er, walk-ed.
• Infix – inside the base. English has almost none (only playful forms like abso-bloody-lutely), but Tagalog uses them regularly: -um- in sumulat (from sulat), -in- in sinulat.
• Circumfix – two parts around the base, working as one affix. Tagalog ka-…-an in kabataan ('youth', from bata) and German ge-…-t in gesagt ('said').

4. Inflection and derivation

Bound morphemes do two different jobs.

Inflectional morphemes add grammatical information (number, tense, person, comparison) without making a new word. English has only eight, and all are suffixes:

Derivational morphemes make new words. They may change the word class (teach v. → teacher n.; happy adj. → happiness n.; modern adj. → modernize v.) or the meaning (happy → unhappy; write → rewrite). English has hundreds of them, prefixes and suffixes alike.

• Derivation comes before inflection: teach-er-s, never *teach-s-er.
• A word takes at most one inflection at a time, but can take several derivational affixes (nation-al-iz-ation).
• Identical forms can be different morphemes. The -er of taller is the inflectional comparative; the -er of worker is a derivational suffix meaning 'one who'. The -ing of is walking is inflectional; the -ing of a building forms a new noun.

5. Allomorphs and irregular forms

One morpheme can have several pronunciations, called allomorphs. Which one appears is decided by the sound before it.

• Plural, possessive and third person -s: /ɪz/ after the sibilants /s z ʃ ʒ tʃ dʒ/ (buses, judges); /s/ after other voiceless sounds (cats, books); /z/ after other voiced sounds (dogs, bees).
• Past -ed: /ɪd/ after /t/ or /d/ (wanted, needed); /t/ after other voiceless sounds (walked, kissed); /d/ after other voiced sounds (played, opened).

Irregular forms express the same morphemes in other ways.

• Internal vowel change: foot → feet, man → men, sing → sang → sung.
• Suppletion, a completely different form: go → went, good → better → best, be → was.
• Zero morph, no change in form: one sheep, two sheep; deer; past hit, cut, put.
• Old English -en: ox → oxen, child → children.
• Borrowed plurals: criterion → criteria, phenomenon → phenomena, analysis → analyses, stimulus → stimuli, datum → data.

6. Word structure has layers

Affixes attach one at a time, so a complex word has an internal structure that can be drawn as a tree. Unhappiness is built as [[un-[happy]]-ness]: un- attaches to the adjective happy, giving unhappy, and -ness then turns it into a noun. -ness cannot come first, because un- does not attach to the noun happiness in this sense.

Different layerings can give different meanings. Unlockable is ambiguous:

• [un-[lock-able]] – not able to be locked (a broken door);
• [[un-lock]-able] – able to be unlocked (a door with a key).

Summary

• The morpheme is the smallest unit with meaning or grammatical function; it is not a syllable.
• Morphemes are free (lexical or functional) or bound; some roots are bound (-ceive, cran-).
• Affixes are prefixes, suffixes, infixes and circumfixes; Tagalog uses the last two regularly.
• English has eight inflectional suffixes; derivational affixes make new words and come before inflections.
• Allomorphs of -s and -ed are chosen by the preceding sound; irregular forms use vowel change, suppletion, zero, -en and borrowed plurals.
• Complex words have layered structure, which can make them ambiguous.