Adjectives are useful to describe nouns. Because adjectives describe the qualities possessed by nouns or pronouns, they can often be compared. By adding -er and -est to existing adjectives, you can use them to compare two or more nouns. For example, by adding -er and -est to the adjective, "low", you can make "lower" and "lowest". Thus, three objects can be compared: e.g. "My wall is low and your wall is lower, but his wall is the lowest". The adjectives "low", "lower" and "lowest" help to compare three of the same type of noun, in this case a wall.
Some adjectives cannot have the -er and -est suffixes added to them. In these cases, it is necessary to add the adverbs "more" and "most". For example, "Bill is interesting", "Bob is more interesting", "Ben is the most interesting". It's not correct to say that someone is the "interestingest"! Adjectives taking -er or "more" are known as comparative, while those taking -est or "most" are known as superlatives.
Select the correct forms in this English quiz.