e:
现在时 I am,you are,he is,we are,you are,they are
（缩略式 I'm,you're,he's,we're,you're,they're）,
（否定缩略式 I'm not,isn't,aren't）,过去时 I was,you were,he was,we were,you were,they were
（过去时否定缩略式 wasn't,weren't）,过去分词 been,现在分词 being
作助动词用,构成各种时态或语态
[与动词的现在分词连用,构成各种进行时态]
[与及物动词的过去分词连用,构成被动语态]
[与动词不定式连用,表示职责、义务、意图、约定、可能性等]
[与不及物动词come,go等的过去分词连用,构成完成体]
[用be和were表示虚拟语气]
become:
vi.
变成,成为,变得
vt.
适合,相称
区别相当大