could not后面加动词原形。
could：
modal用于can的过去时;(询问是否可做某事)能，可以;(礼貌地请求别人做事)能；
v.把(食品)装罐保存;让…卷铺盖走人;炒…的鱿鱼；
can的过去分词和过去式
Her colleagues could not fault her dedication to the job.
她的同事认为她的`敬业精神是无可挑剔的。
Despite her earnest efforts, she could not find a job.
尽管她已尽心竭力，但是仍然找不到工作。
With the best will in the world I could not describe him as a good father.
尽管我心里极想美言几句，却怎么也不能说他是位好父亲。
She could not distinguish the make of the car in the fading light.
她在渐暗的暮色中看不清楚汽车的型号。
温馨提示：
