求大神解释if引导的虚拟语气
问题描述：
求大神解释if引导的虚拟语气
答
if引导 非真实条件句 分3种
与现在相反
if+主语+动词过去时（be用were）+.,主语+could/would/might/should+动词原形+.
与过去相反
if+主语+had been+ 动词过去分词.,主语+could/would/might/should+have+动词过去分词.
与将来相反
if+主语+should/were to+动词原形.,主语+could/would/might/should+动词原形+.