Understanding Inflectional Morphology
Inflectional morphology changes a word's form to express grammatical information without changing its core meaning or word class. Turning "cat" into "cats" doesn't create a new word; it just marks that there's more than one cat. This is different from derivation, which creates new words or changes word classes (like "teach" → "teacher").
These small changes are what make sentences hang together. They signal tense, number, agreement, and other grammatical relationships, ensuring that words fit properly with each other. Without inflection, you'd have no way to distinguish "The cat purrs" from "The cats purr."
Purpose of inflectional morphology
- Marks grammatical features without changing core meaning. "Cat" and "cats" refer to the same kind of animal; the -s simply tells you there's more than one.
- Signals relationships between words in a sentence. Subject-verb agreement is a clear example: "The dog barks" vs. "The dogs bark." The verb form changes to match the subject.
- Expresses categories like tense, number, person, and case. These are the grammatical dimensions that inflection operates on (walked, walks, walking).
- Reduces ambiguity. "I walk" vs. "He walks" tells you who is performing the action, even without extra context.
Grammatical categories in English inflection
English inflection covers several grammatical categories. Here are the main ones:
- Number distinguishes singular from plural (book vs. books).
- Person indicates the speaker (first person: I walk), the addressee (second person: you walk), or someone else (third person: she walks). In English, person only shows up on verbs in the third-person singular present tense.
- Tense expresses the time of an action or state (walk vs. walked).
- Aspect shows how an action unfolds over time. The progressive aspect uses the -ing form (walking), while the perfect aspect uses the past participle (has walked).
- Mood conveys the speaker's attitude toward what's being said. The subjunctive mood, for instance, appears in "If I were you" (using "were" instead of "was").
- Case marks a noun or pronoun's role in the sentence. English pronouns still show case clearly: he (subject), him (object), his (possessive). Regular nouns only inflect for the possessive (dog's).
- Comparison applies to adjectives and adverbs, indicating degree (tall, taller, tallest).
Inflectional Patterns and Forms
Inflectional patterns for word classes
Nouns inflect for two things in English: number and possessive case.
- Regular plurals add -s or -es (dog → dogs, box → boxes).
- Irregular plurals change form in other ways (child → children, mouse → mice).
- The possessive adds 's to singular nouns (the dog's bone) and just an apostrophe to regular plurals (the dogs' bones).
Verbs carry the heaviest inflectional load in English, with four inflectional suffixes:
- -ed marks regular past tense (walk → walked).
- -s marks third-person singular present (she walks).
- -ing forms the present participle (walking).
- -ed / -en forms the past participle for regular verbs (walked, spoken).
Note that regular verbs use the same -ed form for both past tense and past participle. Irregular verbs are where these two forms often differ (wrote vs. written).
Adjectives inflect for comparison:
- The comparative adds -er (tall → taller).
- The superlative adds -est (tall → tallest).
- Longer adjectives (typically two or more syllables) use more and most instead (beautiful → more beautiful → most beautiful). These periphrastic forms aren't technically inflection, since the adjective itself doesn't change, but they fill the same grammatical role.
Irregular inflections and usage
English has plenty of forms that don't follow the regular patterns. These are worth memorizing because they come up constantly.
Irregular noun plurals fall into a few types:
- Vowel changes alter the internal vowel (man → men, goose → geese). This is sometimes called ablaut.
- -en endings add -en to the base (ox → oxen, child → children).
- Zero plurals stay the same in singular and plural (sheep, deer, fish).
Irregular verb forms are especially common among frequently used verbs:
- Some change entirely in the past tense (go → went, eat → ate).
- Past participles often end in -en (write → written, speak → spoken).
- The verb "be" is the most irregular verb in English, with forms drawn from multiple historical roots: am, is, are, was, were, been, being.
Suppletive forms are the most extreme type of irregularity. Instead of modifying the base word, the language uses a completely different root. The adjective "good" becomes "better" and "best," not "gooder" or "goodest." Similarly, "bad" becomes "worse" and "worst."
Irregular comparative and superlative adjectives also include "little → less → least" and "many/much → more → most." These are high-frequency words, so despite being irregular, most speakers use them without thinking.