We often consider it as a mistake in this case.

请分析句子成分，尤其是其中的介词短语 as a mistake 是什么成分？

【答】若把as a mistake in this case 忽略，这是一个“主+谓+宾”结构：S+V+O

in this case 是定语修饰mistake。

下面，重点谈谈as a mistake 的成分问题。as 是“作为”的意思，经常跟“认为、观点、看法”类的动词连用。关于as a mistake 的成分归属，现在，可能有两种意见：一种是把as 短语看作宾语补足语，补充说明it；另一种是状语，修饰动词consider，说明“认为”的方式或结果。

我们可以用一个最实际的方法，去分析这个问题。as 短语跟宾语it 和谓语consider，确实都有一定的关系。那么，跟谁的关系比较密切呢？这就需要讨论甚至争论了。对于这个问题，可谓仁者见智。例如：

I treat him as a guest of mine. 我把他当作我的客人。

有许多人都把as a guest of mine，看作宾补。其实，这句话也可以理解为：“我以客人的方式对待他”。那么，as 短语的作用就是“以何种方式看待某人，对待某人”，就是说，as 短语是针对谓语动词treat而言的，并非针对宾语，所以看作方式状语比宾补更好。这里的as 意为“以...身份，作为...方式”。 传统语法书都把as 介词短语，看作宾语补足语。

我认为：“宾补”的观点重在强调与宾语的关系；“状语”的观点重在强调动作的方式或结果。

英语这样的表达或结构跟多，as 后除了接名词代词外，还可接形容词和动名词，有的动词还可以接as从句。

最常见的这类表达是“观点类”用法。该类动词表示“认为，认可，承认，确认，当作，看作，视为，理解为”等含义。为了理解方便，我们用him 作宾语。

观点类“regard sb. as... 型结构”归纳如下：

regard him as

consider him as

identify him as

view him as

recognize him as

confirm him as

think of him as

look on him as

look upon him as

esteem him as

reckon him as

acknowledge him as

know him as

conceive of him as

see him as

treat him as

count him as

value him as

accept him as

take him as

label him as

perceive him as

fancy him as

imagine him as

understand him as