做某事有困难，可以用以下英语句型来表达：

1. I find it difficult to do something.（我发现做某事很困难。）

例如：I find it difficult to speak in public.

2. I struggle with doing something.（我做某事很费劲。）

例如：I struggle with doing math problems.

3. I have a hard time doing something.（我做某事很困难。）

例如：I have a hard time understanding complex instructions.

4. Doing something is a challenge for me.（做某事对我来说是一个挑战。）

例如：Running a marathon is a challenge for me.

5. I am not very good at doing something.（我不擅长做某事。）

例如：I am not very good at playing basketball.

6. Doing something is beyond my ability.（做某事超出了我的能力范围。）

例如：Speaking fluent Chinese is beyond my ability.