as … as：表达相等

比较级（如 taller、more expensive）表示两样东西不一样。可如果它们一样呢？英语专门有一个结构来表达这个：as … as。

要记住的一条规则： 要说两样东西相等，把形容词或副词的原级夹在两个 as 中间：as + 形容词/副词原级 + as。不加 -er，也不用 more——只用原级。✅ as tall as，绝不是 ❌ as taller as。

表达相等：as … as

两样东西在某方面相等时，用 as + 形容词 + as：

My brother is as tall as me.
This café is as good as the one downtown.
Her new phone is as fast as mine.

形容词保持原级——绝不用比较级。✅ as expensive as，绝不是 ❌ as more expensive as。

汉语常说“跟/和……一样 + 形容词”，如“这个跟那个一样贵”；英语则要说 as + 形容词原级 + as + 比较对象，如 as expensive as that one。注意不要按汉语顺序漏掉第一个 as。

这个结构不只用于形容词，也适用于副词：She finished as quickly as she could. · He didn't drive as carefully as usual.

本课只讲形容词和副词。数量的表达是另一种句型，本课不涉及：as much time as、as many books as。

否定形式：not as / so … as

要说两样东西不相等，在第一个 as 前加 not。也可以把第一个 as 换成 so——两种都对，但 not so … as 听起来更正式、更老派一些：

This test wasn't as hard as the last one.
He isn't as busy as he used to be.
The film wasn't so exciting as I expected.（比 as … as 略正式）

注意这个否定形式的真正含义：not as hard as 只是说第一样东西没有第二样那么难，并没有说差距有多大。要表达差距的大小，需要下面的修饰语。

削弱或加强比较

可以在第一个 as 前加一个词，说明两样东西有多接近相等：

修饰语	含义	例句
just as	相等，带强调语气	This one is just as good* as that one.*
nearly as / almost as	非常接近，但稍逊一点	She's almost as tall as* her mother.*
not quite as	接近，但稍逊一点	The sequel isn't quite as funny as* the original.*
not nearly as	差得远——差距很大	This café isn't nearly as cheap as* the one near my home.*

This laptop is just as fast as the old one — they feel equally fast.
He isn't nearly as tired as he looks——这句强调差距很大。普通的 isn't as tired as 只是说他没那么累，并没有说差距有多大。

表示倍数差距：twice as、half as、three times as

要精确说明某样东西大或小多少倍，把倍数放在 as … as 前面：

This flat is twice as expensive as my old one.（两倍）
The queue moved half as fast as yesterday.（一半）
Their new office is three times as big as the old one.（三倍）

在 B1 阶段，更清晰自然的说法是 倍数 + as + 形容词 + as：twice as big as。在更高级或专业的英语里，也会见到 three times bigger than 这样的说法，但可能显得含糊，所以本课坚持用更清楚的 as … as 结构。✅ twice as big as；在这个阶段，不建议用 ❌ twice bigger than。

as … as 与 -er / more 的区别

两种结构都用来比较两样东西，但回答的问题不同：

结构	回答的问题	例句
-er / more + than	谁在这一点上程度更高或更低？	This one is bigger than* that one.*
as … as	它们相等吗，或者有多接近相等？	This one is as big as* that one.*

-er / more 比较级前也可以加修饰语，来弱化或强化比较，并说明差距有多大（a bit bigger、much more expensive、far cheaper）——参见修饰比较级，等 as … as 用熟了之后再学。

关于 as 后面代词的说明： 在日常口语中，宾格代词很自然：as tall as me、as good as her。在更正式的书面语里，也会见到主格代词加动词：as tall as I am、as good as she is。两种都对——宾格代词的说法只是听起来更随意一些。

常见错误

❌ She is as taller as me. → ✅ She is as tall as me.（用原级，不用比较级）
❌ This is as more expensive as that. → ✅ This is as expensive as that.
❌ It's twice bigger than the old one. → ✅ It's twice as big as the old one.（这个层次，倍数要和 as … as 搭配）
❌ He isn't so good than her. → ✅ He isn't as good as her / ✅ He isn't so good as her.（as … as / so … as，绝不是 so … than）
❌ This bag is not as cheap than that one. → ✅ This bag is not as cheap as that one.

小测验

用正确的形式补全每个句子：

My sister is ____ (tall) ____ me.（两人身高完全一样）
This coffee isn't ____ (strong) ____ the one at home.（这杯更淡）
The new bridge is ____ (long) ____ the old one.（正好两倍长）
He's ____ (fast) ____ his brother — just a tiny bit slower.（用 almost）
This flat is ____ (big) ____ my last one — a huge difference.（用 not nearly）

显示答案

as tall as 2. as strong as 3. twice as long as 4. almost as fast as 5. not nearly as big as

要点回顾

表达相等用 as + 形容词/副词原级 + as——绝不用比较级：✅ as tall as，绝不是 ❌ as taller as。
否定形式是 not as / so … as：not as hard as、not so exciting as。
用 just as（相等）、nearly / almost as（非常接近）、not quite as（稍逊一点）、not nearly as（差距很大）来削弱或加强语气。
用倍数表示精确差距：twice as、half as、three times as——比把倍数放在 -er / more 前面更清楚。
as … as 问的是“它们相等吗？”；-er / more + than 问的是“谁的程度更高？”——问题不同，结构也不同。