1. Here are the generalizations from the previous three lessons:
i. Stems that form nouns with <ation> take -able to form adjectives
ii. Verbs that end in <ate> take -able to form adjectives.
iii. Verbs that end in <y> take -able to form adjectives.
iv. In verb-noun-adjective families, if the noun ending in <ion> uses a different base than the adjective, the adjective takes -able; if the noun uses the same base as the adjective, the adjective takes -ible.
2. Applying these generalizations, fill in the blanks below with whichever is correct:
3. All of the words with -ible come from French and Latin (as do many of those with -able). However, -able is the form we use for making adjectives from native English words and for making up new words. The following words are all native English words. Add the suffix that changes them to an adjective ending in [əbəl]:
Adjective with [əbəl]
Native adjectives use the suffix -able.
This is a very strong generalization. But it is not very useful if you can't recognize native words. One hint: Notice that native words tend to be very short, only one syllable. Compare them with the words in the tables in Lesson 36. Words from Latin and French most often have two or more syllables.
4. The following are a few adjectives that have just recently been made up. Analyze each one into its stem plus suffix and be ready to talk about what you think they mean:
Analysis: Stem + Suffix
address + able
air-drop + p + able
camouflage + able
cartop + p + able
thermoform + able
5. One last word about -able and -ible: Remember that -able is about six times more common than -ible and that it is usually a good bet.