Read the slot
An article/possessive followed directly by a gap often signals a noun; if a noun follows the gap, an adjective may be needed. An action verb is often modified by an adverb. Linking verbs be, seem, become, feel, look and smell can take adjectives describing the subject. These are clues, not rules based on one neighboring word.
Common families
Suffixes help identify a form, but do not guarantee meaning. Learn the whole family and its spelling. Not every word ending in -ly is an adverb: friendly is normally an adjective; fast can be an adjective or adverb.
| Noun | Verb | Adjective | Adverb |
|---|---|---|---|
| success | succeed | successful | successfully |
| decision | decide | decisive | decisively |
| beauty | beautify | beautiful | beautifully |
| danger | endanger | dangerous | dangerously |
Negation and contrast
Un-, in-, im-, il-, ir-, dis- and -less can create negative meanings, but their distribution must be learned: unhappy, impossible, illegal, irregular, dishonest, careless. Check the context’s polarity. Sensible and sensitive, economic and economical have different meanings, not simply different endings.
Participles and spelling
An -ing adjective commonly describes the cause of a feeling; -ed describes the affected person: a tiring journey, tired travelers. Check noun countability and plural endings. Watch spelling changes such as happy → happiness, decide → decision, possible → possibility. Do not add an unnecessary plural to an uncountable noun.
Worked example
The gap modifies the action explained, so an adverb is required. Clearly answers “how?”. Clear is the adjective, clarity the noun and clarify the verb.
The instructor explained the route clearly.
Compare: The explanation was clear.
Final checklist
- What part of speech fits the whole structure?
- Is the meaning positive or negative?
- Is number/countability correct?
- Is the exact word’s spelling and collocation correct?