have既是助动词也是动词。作动词时有“有；持有；占有；由……组成；显示出，带有（性质、特征）”的意思。作助动词时与过去分词连用构成完成时。

have助动词用法

1、（加过去分词，构成完成时态）已经；曾经

have/has done现在完成时 had done过去完成时will have done将来完成时would have done过去将来完成时have/has been doing现在完成进行 had been doing过去完成进行

They haven't finished the job yet.

他们尚未完成该项工作。

2、（用于虚拟语气，表示与过去事实相反的假设）（假如那时）……的话

She might have come if she hadn't been so busy.

当时若不是那么忙，她是可能来的。

have动词用法

1、有，拥有

This coat has no pockets.

这件衣服没有口袋。

注意：have “有，拥有”，其疑问和否定形式有两种，如：

Do you have a brother? No, I don’t have a brother.

Have you a brother? No, I haven’t a brother.

2、怀有，持有

Many people have doubts about the new project.

许多人对这项新工程有怀疑。

3、体验；经验；患

We had a wonderful time on the beach.

我们在海滩上玩得好极了。

4、拿；得到，取得

We gave him a present, but he wouldn't have it.

我们给他一件礼物,但他不肯接受。

5、进行，从事（某事）

The manager is having a meeting.

经理正在开会。

6、吃；喝；吸（烟）

They had their lunch in a cafeteria.

他们在一家自助餐厅吃了午饭。

7、邀请（某人），，招待

We had some guests for dinner last night.

我们昨晚请了几位客人吃饭。

8、（用于否定句中）容忍；允许

I won't have anyone smoking in here.

我不容许任何人在这里抽烟。

9、生得，生育

My wife is going to have a baby.

我妻子快要生孩子了。

10、使，让；招致

I've had the stove lighted.

我已经让人把炉子点着了。

11、要；叫；使

I'll be proud to have you read it.

你肯读它我会感到骄傲的。

12、必须,不得不

I have to go right now.

我马上得走。

13、明白，懂得

I guess I have your ideas.

我想我明白你的意思。