"be"是英语中的一个连系动词，用于连接主语和表语，表示主语的身份、状态或特征。

"be"没有所谓的“原形”，因为它本身就是原形。然而，当“be”与其他动词搭配使用时，可能需要根据句子的时态和语态进行适当变化，如：

1. 现在时：I am, you are, he/she/it is, we are, they are

2. 过去时：I was, you were, he/she/it was, we were, they were

3. 将来时：I will be, you will be, he/she/it will be, we will be, they will be

4. 过去将来时：I would be, you would be, he/she/it would be, we would be, they would be例如：I am a student. （我是学生。）He was sick yesterday. （他昨天生病了。）We will be late for the meeting. （我们将会开会迟到。）They would be angry if we told them the news. （如果我们告诉他们这个消息，他们会生气的。）