Question

if i were a teacher 为什么用were

Answer 1

如果我是他 If i were he,跟第几人称无关.跟时态有关.
1、表示与现在事实相反的情况：
从句：If 主语+过去时
主句：主语+should/would/could/might+do
eg．If I were you,I would take an umbrella.
如果我是你,我会带把伞.（事实：我不可能是你）
2、表示与过去事实相反的情况
从句：If 主语+had+done
主句：主语+should/would/could/might+have done　
eg.If I had got there earlier,I should/could have met her.
如果我早到那儿,我就会见到她.　（事实：去晚了）
3、表示对将来情况的主观推测
从句：①if+主语+were to do 主句：
①主语+should/would/could/might+do
②if+主语+did/were ②主语+should/would/could/might+do　
③if+主语+should+do ③主语+should/would/could/might+do　
eg．If he should come here tomorrow,I would talk to him.
如果他明天来这儿的话,我就跟他谈谈.（事实：来的可能性很小）
注意,在虚拟语气的从句中,动词be的过去时态一律用were,不用was.
eg：If I were you,I would go to look for him.

Answer 2

你好，很高兴在这里回答你的问题：

.

虚拟语气
对我是老师进行虚拟，但我并不是