2.在It's surprising/ strange/ a pity...以及I'm surprised/ sorry...等句型中,当"竟然会"讲.例如：
①It's surprising that you should be so foolish.真令人吃惊,你竟会如此愚蠢!(现在)
②It's surprising that you should have failed to pass such an exam.真令人吃惊,这样的考试你竟然不及格.(已发生)
3.单独用"should (not) +have+过去分词"形式,对已发生的事表示遗憾或责备,表达"本该或不该"之意.例如：
①He also learns that he should have cared more about his friends.他还明白了他本应该多关心朋友.(高一课本上册P4)
②He shouldn't have let out the secret.他本不该泄露秘密的.(实际情况是"他已泄密".)
二、用于揣测,表示可能或期望,意思是"照理说来、应该".
在语气上should比must弱,但比may/ might强；shouldn't比
can't弱,但强于may/ might not.例如：
①I should be home in about ten minutes.照理说来,约十分钟后我就能到家.(高一课本上册P59)
②He should be having class now.他现在应该是在上课.
③As far as I know you shouldn't have any problems there.就我所知,在那里你不会遇到任何问题.
④According to the schedule,they should have arrived in Shanghai by now/ yesterday.按照计划,他们现在/昨天应该已经到达上海了吧.
(注：本句中的"should+have done"结构并不表示责备,仅表示说话人的揣测.)