be动词有哪些形式?答:be动词的用法 be [bi:]vi 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...
be动词有哪些形式?答:be动词的用法 be [bi:]vi 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...