1) The Sahara is the biggest desert in the world.

形容词最高级前通常必须用定冠词 the，副词最高级前可不用。

形容词most前面没有the，不表示最高级的含义，只表示"非常"。

• It is a most important problem.
  =It is a very important problem.

注意： 使用最高级要注意将主语包括在比较范围内。

(错)　Tom is the tallest of his three brothers.
(对)　Tom is the tallest of the three brothers.

2) 下列词可修饰最高级，by far, far, much, mostly, almost

• This hat is nearly / almost the biggest.

注意：

a.　 very可修饰最高级，但位置与much不同。

• This is the very best.
  This is much the best.

b.　 序数词通常只修饰最高级。

• Africa is the second largest continent.

3) 句型转换：

• Mike is the most intelligent in his class.
• Mike is more intelligent than any other students in his class.

4) "否定词语+比较级"，"否定词语+ so… as"结构表示最高级含义。

• Nothing is so easy as this.
  =Nothing is easier than this.
  =This is the easiest thing.