Question

have和has的用法和区别有哪些？

Answer 1

助动词have有五种形式：动词原形——have、第三人称单数现在式——has、过去式——had、过去分词——had、现在分词——having。
助动词have的主要用法是：

1）与过去分词构成各种完成时态。如：

（1）Newton has explained the movements of he moon from the
attractions of the earth. 牛顿阐明了月球受到地球引力而运行的规律。

（2）Reluctantly, she opened the door, she had not kept it locked;
there had been no need. 她勉强地开了门。她没有锁门，也没有必要锁门。

2）与been+现在分词构成各种完成进行时态。如：

（3）Men have been digging salt out of it for six hundred years, and
yet there seems as much left as ever. 人们在这里掘盐已六百年，但盐似乎还是那么多。

（4）In another month’s time Mr. Henry will have been teaching here
for exactly thirty years. 再过一个月，亨利先生就将在这里从事教学整30年了。

此外，have还可用作实义动词，意谓“有”、“吃”等。如：

（5）Bad news has wings. 丑事传千里。

（6）You’re anaemic, you must have some iron. 你患贫血症，应该服一些铁。

have还可用作使役动词。如：

（7）We now have the problem solved. 我们现已把这个问题解决了。

（8）I had a tooth out this afternoon. 我今天下午拔了颗牙。