as do I 与 as I do（我也一样）　　

有朋友在本站“答疑中心”询问：表示“……也一样……”时，英语通常用 so do I 这类表达，英语能否用 as do I 呢？进一步的问题是这类倒装适用于主语是代词的情况吗？　

前一阵子外出了，在QQ上收到英语语法网站长陈先生的留言，说是希望能帮忙找一个“权威”的例句，证明 as do I 是对的。今天刚回长沙，于是开始查找，还真查到了一个相关的说明。现摘录如下（重点注意加粗部分）：　　

A third group can be characterized as words that link content across clauses – not only, neither, nor, so, and as, all of which arc shown in (55). The clauses in (55b), (55c), and (55d) of course involve ellipsis as well as inversion, so that, for example, (55c) corresponds to and we can do it (, too). For many native speakers, inversion after as is no longer obligatory, at least with the auxiliary do, as illustrated in (55d).　　

(55) a. Not only am I unhappy with his behavior, but I frankly just don't understand it.　　

b. A: I don't understand why she reacted that way. B. Neither do I. / Nor do we.　　

c. She can do it, and so can we.　　

d. He believes firmly in the goals of the project, as do I (inverted) / as I do (uninverted).　　

以上内容摘自剑桥大学出版社出版的《教师英语语法》（The Teacher's Grammar of English）。很显然这应该算是权威的，我们从其中的用法说明以及例句可以得出以下结论：　　

1. 这类倒装完全适用于主语是代词的情况。　　

2. 这类倒装还是非强制性的，即可以倒装也可以不倒装。