关于这个问题，好像不同的权威辞书也存在分歧：

▲认为不能用复数的观点

1.《牛津英语用法指南》认为：英语不能说：I have difficulties (in) remembering faces.（黎老师在前面已提到过）

2.《剑桥中级英语语法》（Raymond Murphy著；外语教学与研究出版社）第305页有这样一道选择题：

I’m sure you’ll have no ______ the exam.

A. difficulty to pass                 B. difficulties to pass

C. difficulties passing             D. difficulty passing

该书对此题所给答案为D，将复数difficulties作为干扰项设置，显然作者认为此类结构不能用复数difficulties。

▲认为可以用复数的观点

1.《朗文英语正误词典》（Longman Dictionary of Common Errors）有have difficulty / difficulties (in) doing sth (NOT a difficulty)的用法说明（李翔老师在前面已提到过）。

2.《牛津英语搭配词典》有如下例句：

Police have difficulties in dealing with domestic disputes. 警察很难处理家庭纠纷。

3.《牛津短语动词词典》有如下例句：

The term “visually handicapped” refers to students who have serious difficulties in seeing. “视障生”一词指的是有严重视力缺陷的学生。

4.《柯林斯·英语语法大全》有如下例句：

At present the computer has difficulties in detecting similarities and differences of meaning. 目前计算机在检查词义的异同方面还有困难。

▲小小建议

如果是学生参加考试，建议使用 have some difficulty，不用 have some difficulties。