A Most adjectives can be used in two positions: attributive adjectives occur before the noun they describe, while predicative adjectives are used after certain verbs:ablackcat[attributive]The cat wasblack. [predicative]
B There are some adjectives that can only be used in one position or the other. For example, these two sentences are grammatically correct:✓She wasalonethat evening.['alone‘ = predicative ]✓It was amerescratch.['mere‘ = attributive]These sentences, on the other hand, are not correct:✗I saw analonewoman.['alone‘ cannot be used in the attributive position]✗The scratch wasmere. ['mere‘ cannot be used in the predicative position]
C Most adjectives are gradable. This means that their meaning can be modified (made stronger, weaker, or otherwise altered) by placing one or more adverbs in front of them. For example:an expensive house - averyexpensive house - afairlyexpensive house - anextremelyexpensive houseThe adverbsvery, fairly, andextremelytell where this particular house belongs on the scale of 'expensiveness‘. By using them, we can make a significant difference to the meaning of an adjective.Non-gradable adjectives are those with meanings which cannot be modified by adverbs. For example:thewesternside of the mountain -electronicdevices - anuclearreactor
D All the adjectives have two different forms: the comparative, and the superlative:comparative          superlativesad              sadder                   saddesthappy          happier                  happiestunusual       more unusual        most unusual
E The comparative form is used for comparing two people or things:He istallerthan me. The superlative is used for comparing one person or thing with every other member of their group:He was thetallestboy in the class.