be动词包含以下形式：

am

is

are

was

were

be

been

being

这些动词用于不同的时态和语境中，例如：

am, is, are 用于现在时态；

was, were 用于过去时态；

be 用于无时态的句子中；

been, being 用于完成时态和进行时态