释放双眼，带上耳机，听听看~！
这个语法顺口溜太顶了！拒绝死记硬背！
be 的用法口诀
用am，你用are， is连着他/她/它
——I am/You are /He is a student.
单数名词用is，复数名词全用are
——This is a book. / These are books.
变疑问，往前提，句末问号莫丟弃
——Are you a student?
变否定，更容易，be后not莫忘记
——I am not a student.
疑问否定任你变，句首大写莫迟疑
——Are you/Is he a student?
