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。

difficulty可数与不可数都行.“have some difficulty” 表示“有某种困难”,“have some difficulties ”表示“有一些困难”,意思不同!

difficulty n.困难,艰难,难事；有可数名词和不可数名词两种用法。
①用作不可数名词，意为"困难、艰难",常用在以下句型中
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.
②用作可数名词。表示具体的困难，意为"难事,难点,困境,难处"
This book is full of difficulties.
In face of so many difficulties,we never appeared to be afraid.

have some difficulty 中，difficulty即可用单数，也可以用复数形式，但意思稍有不同：

1）difficulty用作不可数名词，意为"困难、艰难",如：

I have some difficulty in expressing myself.

我表达起来有点儿困难。

But we have some difficulty in choosing the play.

但是我们在选择剧目上有困难。

2）difficulty用作可数名词，用复数形式difficulties,表示具体的困难，意为"难事,难点,困境,难处",如：

We may have some difficulties making payment in Japanese yen.
用日元付款对于我们来说可能会有一些困难。

Mary have some difficulties with her writing.

玛丽在写作方面有些困难。

have some difficulty 是用复数
即
have some difficulties