having+过去分词与have+过去分词有什么区别？

having + 过去分词，这是动名词的主动语态的完成式。have+过去分词，是表示现在完成时态。看两个例子，1.She didn't acknowledge having received my letter.她不承认以接到我的信。2.She have received my letter.她接到了我的信。可看出各自在句中充当的成分不同。第一个句子里having received my letter.是宾语，是名词性质的。而第二句中have received.是谓语，是动词。

1、“having+过去分词”是非谓语动词形式，即现在分词或动名词的完成式。做现在分词时，在句中作状语、定语、补足语；做动名词时，在句中作主语、宾语。如：Having finished his homework, Tom went to play football with his friends. 2、“have+过去分词”是谓语动词的时态形式，即现在完成时。在句中只能做谓语。如：Great changes have taken place in my hometown in the past twenty years.