back是一个副词，可以和任何动词搭配。向后，往后
come back 回来
fly back 飞回来
fight back 反击
run back 跑回来
pull back 拉回来，从错误的道路上拉回来
push back 推回来（把我推回来） ，push forward 往前推（把桌子往前推），push out（向外），把他给我退出去
take back 夺回来，拿回来
talk back 顶嘴
look back 回头看
give back 给，还回去
get back 弄回来
lean back 往后靠。left/right/up/down
turn back 转过身去
jump back 跳回来
ask back 反问
句子
- 疑问句
- 带动词：主谓宾
- 不带动词：主系表
- 陈述句
- 带动词：主谓宾
- 不带动词：主系表
不带动词：
疑问词+时表词+主语+（名词（a teacher）/形容词（tall）/副词（here）/介词短语（at home））状态
一般现在时，有动词用do/does ，没动词用be
一般过去时，有动词用did，没动词用were/was
does he come from China?介短可以放前面
is he from China?
is he a teacher?
How/Why wasn't he a teacher? 之前怎么会/为什么不是一名老师
how是惊讶，why表原因,需要一个解释
how are you here? why are you here?
are you at home?
are you ready?
how is this phone expensive?
how was this phone expensive? 刚开始怎么这么贵
is it sunny today?
how is it so sunny today?
aren't you pregnant?你没怀孕吗