Question

I+have+a+circle.改否定句？

Answer 1

我有两个否定句：

1. I have not a circle. 

2. I don't have a circle.

第一句是英国英语的说法，第二句是美国英语的用法。

Answer 2

I have a circle.
否定句是
I don't have a circle.

行为动词作谓语一般现在时态的否定句，主语是第一人称单数，直接在主语后加上助动词动词。