as....as的用法总结
中间只能用形容词或副词的原级，不能用比较级或最高级。如果在第二个as之后使用独立的人称代词，一般说来用主格(较正式)或宾格(非正式)均可；
如：
He’s as old as she [her]. 他年纪跟她一样大。
扩展资料
但是，若第二个as之后的人称代词跟有谓语动词，则该人称代词只能用主格。如：
He is as old as she is.
但是有时用主格或宾格含义差别很大：
You love him as much as I (=as I love him). 你爱他像我爱他一样。
You love him as much as me (=as you love me). 你爱他像爱我一样。
用于否定句
在肯定句中用as…as, 在否定句中用not as…as或not so…as 均可。如：
He doesn’t study as [so] hard as his brother. 他学习不如他弟弟努力。
关于比较对象
使用该结构要注意比较对象的一致性，即比较的双方必须是可以比较的同类人或物，否则会出错。如：
你的房间与我的一样大。
正：Your room is as large as mine
误：Your room is as large as me.
涉及数量或程度
如果涉及数量或程度可用：as much+ (不可数名词+) as / as many+ (可数名词复数+) as。如：
You must speak English as much as possible. 你必须尽可能地多说英语。
You’ve made as many mistakes as I have. 你犯的错误和我犯的一样多。
关于修饰语
修饰as…as结构的常见词语有nearly, almost, just, exactly, half, quite, twice, three times等，请注意这些修饰语都只能放在as…as 结构之前 (而不能置于其中或其后。如：
I earn half as much as you do. 我只赚你的一半钱。
This rope is twice as long as that one. 这根绳子比那根长一倍。
