difficult后接不定式的惯用法

问题描述

我在作文中写了这样一句：

He is difficult to finish it in time.

老师说这个句子不符合英语惯用法，应改为：

It is difficult for him to finish it in time.

我想除了惯用法外，还有其他理由吗？谢谢！

老师答疑

李老师：

不仅仅是惯用法的要求，主要是有单词本身所决定。

英国柯林斯出版公司编著《柯林斯COBUILD高阶英汉双解学习词典》(柯克尔等译)(外语教学与研究出版社 2011年7月第1版)P716:

1. Something that is difficult is not easy to do, understand, or deal with. 困难的，不容易的

Hobart found it difficult to get her first book published.

We're living in diffucult times... It's very difficult being a woman in motor racing.

笔者注：此时的difficult只能用表示事物（事情）的名词作主语或修饰表示事物（事情）的名词，总之，不能用像表示人等有灵性的名词作主语（即无灵主语句）或作定语修饰之。上面例句中的diffficult就属于这一用法。

2. Someone  who is difficult behaves in an unreasonable and unhelpful way. 难相处的；难取悦的，不随和的

I had a feeling you were going to be difficult about this. 

试比较difficult的两种用法：

用法一：

a.This lessson is difficult to understand.(difficult 用法1)

b.It is difficult to understand this lessson.(difficult 用法1)

用法二：

a.They are diffficult to beat.(difficult 用法2)

b.It is difficult to beat them.(difficult 用法1)(笔者注：根据陈敦金主编的《英美语惯用法词典》(增订版)(福建教育出版社2002年3月第3版)P344-345有关例句编辑)