带be动词的句子转换规则如下：
一、一般疑问句
肯定句：
将be动词提前至句首，主语随后，其余部分保持不变。
- 例：
- I am a student. → Are you a student？
- The cat is fat. → Is the cat fat？
否定句：
在be动词后加not，其余部分不变。
- 例：
- I am not a teacher. → Are you not a teacher？
- The students are not playing games. → Is the cat not fat？
一般疑问句：
通过be动词提问，主语放在句尾。
- 例：
- She is 16 years old. → Is she 16 years old？
- The picture is on the wall. → Is there a picture on the wall？
二、否定句
变否定句：
在be动词后加not，其余部分不变。
- 例：
- We are late today. → Are we not late today？
- They are students here. → Are they not students here？
三、特殊注意事项
主谓一致 - 单数主语（如I, he, it）用am/is/are
- 复数主语（如we, you, they）用are
缩写形式
- I'm = I am
- You're = You are
- He's = He is
- She's = She is
- It's = It is
- We're = We are
- You're = You are
- They're = They are
四、综合练习
肯定句： He and I are friends. → Are he and I friends？
否定句：
This is not her bag. → Is this not her bag？
一般疑问句：
What shape is it？ → Is what shape it？
通过以上规则，可灵活转换带be动词的句子结构。