1. I find learning English difficult.
= I find learning English (to be) difficult.
= I find it difficult to learn English.
= I find (that) it is difficult to learn English.
= I have trouble/difficulty with (my) English.
= I have trouble/difficulty (in) learning English.
= I find (that) to learn English is difficult.
= I find (that) learning English is difficult.
2. 不定式to have her written English improved为后置定语,修饰a good way.
一起翻译即“一个使自己书面英语改善/提高/改进的好方法”.
不定式中又含有“使役动词have + 宾语her written English + 宾语补足语improved”结构.
注：a/the way to do sth = a/the way of doing sth“做某事的方法/方式”
3. 不知道你这是设问还是反问?
设问：Who among us that have a knowledge of physics doesn't know this/it?
反问：Doesn't anybody among us that have a knowledge of physics know this/it?
4. regardless of the danger to himself并非句子的宾语补足语,而是介宾短语做让步状语“不管/不顾对他自身而言的危险”.
句子的made并非使役动词,而是一个固定短语make after,意思是“追逐”.