What is the function of the suffix -able in English morphology?

• A. The suffix -able forms adjectives from verbs by indicating capability.
• B. The suffix -able marks tense.
• C. The suffix -able pluralizes nouns.
• D. The suffix -able negates meaning.

Answer: (A)

The suffix -able is a derivational ending that turns verbs into adjectives, signaling that something is capable of being acted upon or is possible to do. It expresses capability or possibility, as in readable (able to be read), solvable (able to be solved), or washable (able to be washed). This shows how -able shifts a word from describing an action to describing a property of being able to undergo that action. It doesn’t carry tense, which is a feature of verbs with endings like -ed or -ing, and it doesn’t pluralize nouns (that’s the job of -s or -es). It also doesn’t negate meaning by itself; negation is usually done with a prefix like un- (as in unreadable). So the function is to form adjectives from verbs that express capability or possibility.