She can't sleep well before she ______takes an exam .before是介词,take 为什么不加ing

She can't sleep well before she ______takes an exam .before是介词,take 为什么不加ing
She can't sleep well before she ______takes an exam .before是介词,take 为什么不加ing

She can't sleep well before she ______takes an exam .before是介词,take 为什么不加ing
因为before后面的she takes an exam是一个完整的从句,所以当然不加ing.如果只是动词短语,那么必须加ing ,如：
She can't sleep well before taking an exam .
祝楼主进步!
要是答案还满意的话,记得采纳哦,O(∩_∩)O谢谢~!

before 在此是连词，在...之前，后面接的是一个句子，而不是直接接的动词，所以不用ing形式。

如果中间没有那个she就加ing

before在这里是连词