had是过去时态。
had：
v.有;持有;占有;由…组成;显示出(性质、特征)。
aux.had 有时代替 if 用于从句句首，表示某种情况可能发生但并未发生。
have的过去分词和过去式。
扩展资料
Had I known that I would never have come.
要是早知道，我绝不会来的。
He had to go to hospital for treatment.
他不得不去医院接受治疗。
I've had to put my plans into cold storage.
我不得不把我的'计划暂时搁置起来。
I had a long conversation with her the other day.
前几天我与她作了一次长谈。
We had no say in the decision to sell the company.
在决定出售公司的问题上，我们没有发言权。
