问
按照语法规则，在含有 since 从句的主句中要使用完成体形式。如果主句中有情态助动词时该怎么办呢？
答
含有 since 从句的主句中含有情态助动词时,可以使用非完成体形式:
- (Ever) Since my teeth were pulled out I can't eat anything solid. 自从我拔了牙以后就不能吃固体食物。
- I have to use crutches (ever) since I had a car accident. 自从我出了车祸后,我就得用拐杖了。
- They won't smoke (ever) since they saw a film on lung cancer. 他们看了一部有关肺癌的影片后，就坚决不再吸烟了。
- He can't get about much since he had that accident. 他在那次事故后就不能多走动了。