困惑 - than are they, than they are; as is he, as he is. etc.

onlyloss

复习语法有一段时间了，虽然知道在第二个对比结构里需要加be或者do。但是一直对这类结构很不了解。
所以想请教下这里的大牛们，它们之间到底有什么区别啊？？
给大家点更concrete的idea as to what i am talking about.  I made up below sentences from air.. so please be kind enough to execuse my grammatical errors.
Look forward to your inspiring reply.  If possible, please can you also come up with some substitute examples in which these patterns are used?  

谢谢。

He is good at playing football as am I.
He is good at playing football as I am.

He plays football as good as am I.
He plays football as good as I am.

She performed well in the exam as did I.
She performed well in the exam as I did.

She performed in the exam as well as I did.
She performed in the exam as well as did I.

He performed better than did I.
He performed better than I did.

momochinn

同问~~~

kissxkiss

同问
二者有区别么?

simiko

同问同问~ 哪位牛人指点指点吧~

onlyloss

就没人过来帮忙解答下吗。。

onlyloss

等牛人来解答。。。

aeoluseros

He is good at playing football as am I.
He is good at playing football as I am.
从简洁性原则来看，要省略am。

He plays football as good as am I.
He plays football as good as I am.
这两个句子是错的。am和plays系统词与是实义动词不能比。am省略就可以了。

She performed well in the exam as did I.
She performed well in the exam as I did.
要省略did。

She performed in the exam as well as I did.
She performed in the exam as well as did I.
要省略did。

He performed better than did I.
He performed better than I did.
要省略did。
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如果是关于比较结构后面是subject + verb.还是verb.+ subject，都是可以的，如果verb在前面则是一种强调。
上面这几句由于都是主谓结构比较简单的句子，所以删去am/did没有问题，不会有任何歧义。根据间接性原则，都应该删去。