have done 是从过去发生，截止到现在，比如i have done my homework，我已经写完作业了，表示我现在不用写作业了，而had done是过去的过去发生，截止到过去，比如i had done my homework yesterday我昨天就完成作业了。

have的的用法

1. have +过去分词，构成完成时态。如：

He has left for Japan. 他已去了日本。

We’ve just done the washing-up. 我们刚洗完碗碟。

Poor Jim has just had an accident. 可怜的吉姆刚出了个事故。

I have had this car for three years. 这辆汽车我已用了3年了。

By the end of last month, they had finished the work. 上月未他们就已经完成了工作。

2. have + been +现在分词，构成完成进行时。如：

I have been studying English for 8 years. 我学英语已达八年了。

The children have been having a lot of run. 孩子们一直玩得很开心。

We had been doing business with each other for years before we quarreled. 在吵翻之前，我们多年来在业务上一直来往。

By this time next year, we will have been doing business with each other for 20 years. 到明年这时候，我们的业务住来就满20年了。

I woke up—I had been having a bad dream. 我醒了，我做了个噩梦。

3. have+been +过去分词，构成完成式被动语态。如：

English has been taught in China for many years. 中国教英语已经多年。

I have been made redundant, so I’m going abroad. 我被定成了超编人员，所以我打算出国。

Thousands of pounds have been spent on the new hospital. 这家新医院花费了数千英镑。

None of my friends have been invited to the party. 我的朋友中没有一个被邀参加晚会。

All means have been used to get him to change his mind. 为了转变他的想法，所有的办法都用过了。