用"more"来修饰一个以"-er"结尾的形容词或副词，就是一个比较级使用错误。例如：
- more redder
- more warmer
- more louder
当你比较两件事物时，一个词的"more" 和"-er"形式的作用是相同的，因此没有必要同时使用两者。
当在三个或更多的事物之间比较时，要用"most"或"-est"形式。如"-est"形式一样，"most"的意思也是“最大的程度”。所以，"most"与某个形容词或副词的-est"形式一起使用时，就会出现错误。例如：
- most richest
- most prettiest
- most smartest
大多数单音节词用"-er"和"-est"的形式表示比较级和最高级。两个或两个以上音节的词,还有以"-ful" (wonderful)和"-ly" (sharply)结尾的词要用"more"或"most"构成比较级和最高级。"less"用于两者之间的否定比较，"least"用于三个或更多的事物之间的否定比较。
Of the three houses that my parents toured, that duplex is the least expensive.
几个为数不多的词的比较级和最高级的用法与上文所述规则不符。下面的例子可以帮助你记住它们：
My aunt is a gooder cook than my mother is.
在这个比较中，good应改用better：
My aunt is a better cook than my mother is.
在下面的例子中，当与其他厨师做负面比较时(how bad a cook the mother is) ，应采取这种形式：
In fact, of all the cooks in my family, my mother is the worst!
A faulty comparison error occurs when the word "more" is used to modify an adjective or adverb, that ends with "-er." For example:
- more redder
- more warmer
- more louder
The "more" and the "-er" form of a word function the same way, so it is unnecessary to use both when you are comparing two things.
When three or more things are being compared, use the word "most" and the "-est" form. "Most" is used to mean "to the greatest degree", just as the "-est" form is. An error occurs when the word "most" is used with the "-est" form of an adjective or adverb. For example:
- most richest
- most prettiest
- most smartest
Most one-syllable words form comparison by using "-er" and "-est." Words of two or more syllables and words ending in "-ful" (wonderful) and "-ly" (sharply) form comparison by using "more" or "most." Comparisons that are negative use "less" for comparisons of two things and "least" for comparisons of three or more things.
Of the three houses that my parents toured, that duplex is the least expensive.
A few words, not many, are exceptions to the rules described above. These examples might help you memorize them:
My aunt is a gooder cook than my mother is.
In this comparison, the word good should be the word better:
My aunt is a better cook than my mother is.
In the following example, the description of the negative (how bad a cook the mother is), when compared with other cooks takes this form:
In fact, of all the cooks in my family, my mother is the worst!