Questions: Morpheme Types: Inflection and Derivation

Question 1

Which of the following is a derivational morpheme?

• A. The -s in 'cats' (plural)
• B. The -ed in 'walked' (past tense)
• C. The -er in 'teacher' (one who teaches)
• D. The -ing in 'running' (progressive)

Answer: (C)

The suffix -er in 'teacher' is derivational: it takes the verb 'teach' and creates a new noun meaning 'one who teaches,' changing the word's grammatical category (verb → noun) and substantially altering its meaning. The other three suffixes (-s plural, -ed past tense, -ing progressive) are all inflectional — they mark grammatical properties like number and tense without creating a new word or changing the base word's category.

Question 2

Derivational morphemes generally change the grammatical category of the word they attach to.

• T. True
• F. False

Answer: False

This is a common overgeneralization. While many derivational morphemes do change category (e.g., 'teach' (verb) → 'teacher' (noun)), others create new words within the same category. The suffix -dom in 'kingdom' derives a new noun from a noun ('king'), and the prefix un- in 'unhappy' creates a new adjective from an adjective. The defining property of derivation is creating a new lexical item, not necessarily changing category.

Question 3

What is the core functional difference between inflectional and derivational morphology?

Model answer: Inflectional morphology marks grammatical properties of a word (like tense, number, case, or agreement) required by the syntax, without creating a new word or changing the word's core category. Derivational morphology creates new words — often with a new category or substantially different meaning — that are then listed as separate entries in the mental lexicon.

The practical test is whether the output is a new lexical item: 'teacher' is a different word from 'teach' (it can itself be inflected: 'teachers'), while 'walked' is just the past-tense form of 'walk' — it is still the same verb. Inflectional affixes are typically required by grammatical rules (English subject-verb agreement demands the -s in 'she walks'), while derivational affixes are optional and productive in the lexicon.