have some difficulty 是用单数还是用复数

用单数或者用复数都可以，含义稍有区别。“have some difficulty” 表示“有某种困难”,“have some difficulties ”表示“有一些困难”，意思有差别。

例句：
have some difficulty
1、I have some difficulty which is beyond my expectations and my reach.
我遇到了一些困难，这些是在我意料之外的也是我能力范围之外的。
2、I have some difficulty with my study and I don't know how to talk to my new classmates.

我学业上有点困难而且我不知道如何和我的新同学交谈。
3、I have some difficulty understanding him.

我理解他有些困难。
4、I have some difficulty ( in) answering the question.

回答这个问题我有点困难。

have some difficulties
1、Thanks. I still have some difficulties, however.
谢谢.但是我仍然有些困难。
2、Unfortunately this is a breed which can have some difficulties with health.

可惜这是一个品种能有健康的一些困难。
3、In case I have some difficulties, please give me some explanations.

万一我遇到难题，请给我解释一下。
4、When you have some difficulties in life, the friends will undertake them with you, thisis friendship.

当您生活有啥困难时，好朋友们也会与您一起度过，这是友谊。

单数、复数都是可以的，但是表示的意思不同：

have some difficulty 表示“有某种困难”

have some difficulties  表示“有一些困难”

difficulty表示下面意思时是不可数的：

• 困难,艰难:
  I had no difficulty in getting in touch with him.
  我和他取得联系没有什么困难.

• 常用句型：
  have no/find (some,any,much) difficulty with sth./(in) doing sth.
  There is no (some,any,much) difficulty (in) doing sth.
  I had no difficulty in learning English.
  There was much difficulty (in) explaining it to him.

difficulty 在下面几种意思时是可数的：

1. 难事,难处,难题
   There are a lot of difficulties that have to be overcome.
   有许多困难必须克服.

2. 争论
   Labor difficulties grew.
   劳工纠纷加剧.
   

difficulty在以下意思时本身就是复数形式：

1. (尤指财务上的)困境;危难
   The new government is in financial difficulties.
   新政府财政困难.

2. 异议,反对
   He keeps raising difficulties over the new project.
   他对这项新工程不断地横加阻挠.

have some difficulty
some有某个的意思，也有一些的意思，
这里即可以是单数也可以是复数，
单数：有点困难
复数：有一些困难，不过此时用a few difficulties或many difficulties更好。

difficulty可数与不可数都行.“have some difficulty” 表示“有某种困难”,这里不可数。
“have some difficulties ”表示“有一些困难”, 这里可数。
have some difficulty in doing sth 是固定搭配句型
做...有某种困难

1 都行，含义不同

2 “have some difficulty” 表示“有某种困难”，
“have some difficulties ”表示“有一些困难”，意思不同！

3 have some difficulty in doing sth 是固定搭配句型
做...有某种困难