English grammar: Having lived in China 4 decades, why the beggning is having i/o Have

题目

English grammar: Having lived in China 4 decades, why the beggning is having i/o Have
完整的句子很简单啊，如 Having lived in China 4 dacedes, I want to leave this country.
我想请问这个句子适合于什么语法，为什么省略了 I, HAVE 就变成了HAVING

答案

这是表示一直持续发生的伴随情况的现在分词,属于非谓语动词的一种,在句中充当原因状语.主语在后面,伴随动作也是由主语实施的.如：Having lived in China 4 decades,Jonn can speak Chinese so fluently that none of...