英语的be动词有三个is am are 用法:助词 1.(与动词的现在分词连用,构成各种进行时态)正在...,在...I won't be free this afternoon.I'll be seeing a friend off.我今天下午没空,我要给朋友送行.What were you doing...请问be可以直接用吗，有些填空里面答案不是am/is/are，而是beam is are 的区别 am只用在I 后面, 如 I am a girl 我是女孩 第三人称单数后面跟 is 如 He/She/It/Jim/is 其他跟 are, 如 They/we/girls/boys are什么情况下用Be借助外加助动词如do,did.或者在情态动词如can,will,would,could,should,may,might之后都必须使用be, 而不能直接用am is are. 例如，要说He can be a teacher. 而不能说 He can is a teacher. 同样的，He is a teacher 是正确的说法，He be a teacher 就是错误的说法了。