■ difficulty

与形容词 difficult 相类似，“做某事方面往往遇到的困难”，可以在 difficulty 后面直接放上动词现在分词，不必加上介词 in 再加动名词。

• He has difficulty (in) understanding English.他理解英文有困难。
• She had great difficulty walking.她走路十分吃力。

这个用法，往往是指经常的状态。如果是一时的状态，最好用 to have a difficult time doing（参见 busy 条）。但是也有加上介词 in 再加动名词形式的。

• The writer, an old man with a white mustache, had some difficulty in getting into bed. (Sherwood Anderson, Winesberg, Ohio)作者是个留了白色胡子的老人，上床睡觉有点困难。
• ... and the reader is lost in a maze, from which he has great difficulty in extricating himself. (J.M. D. Meiklejohn, English translator of Immanuel Kant's Critique of Pure Reason, in "Translator's Preface" to the book, p. xi)…读者犹如坠入五里雾中，难以脱身。